The document is about basic physics concepts related to kinetic energy. It contains three main points:
1) It defines kinetic energy (EK) as the energy an object possesses due to its motion, and explains that kinetic energy can be calculated as EK = 1/2 mv^2, where m is the object's mass and v is its velocity.
2) It discusses the relationship between an object's maximum kinetic energy (EKmax) and its maximum velocity (vmax), explaining that EKmax occurs when an object's velocity is at its highest point (vmax).
3) It provides an example calculation of converting between units of kinetic energy, showing how to convert from joules to electron
SchoolDD.com provides concise explanations of trigonometric concepts like sine, cosine, and tangent functions. It explains how to use trigonometric functions to solve problems involving right triangles, with examples calculating values for angles like 30°, 60°, 37°, and 53° degrees. The site also summarizes trigonometric identity formulas and relationships between sine, cosine, and tangent for various angles.
1. The document discusses projectile motion and provides equations to calculate the time, height, horizontal displacement, and velocity of a projectile over time given the initial velocity and angle of launch.
2. Formulas are derived for calculating time, maximum height, and horizontal displacement of a projectile based on the initial velocity components along x and y axes.
3. Examples are provided to demonstrate how to apply the equations to different launch angles like 45 degrees, 60 degrees, and 30 degrees.
This document provides a concise summary of key scientific concepts and formulas in fewer than 3 sentences. It begins by defining common scientific units used to measure length, mass, time, electric current, temperature, amount of substance, and luminous intensity. It then explains the International System of Prefixes used to modify unit symbols and provides examples of their use. The document proceeds to demonstrate the application of scientific concepts and formulas to solve problems involving length, area, volume, speed, time period, percentage error, and other topics. Diagrams are included to illustrate geometric and trigonometric relationships. Key formulas from algebra, trigonometry, logarithms, and other areas are also summarized concisely.
The document is about basic physics concepts related to kinetic energy. It contains three main points:
1) It defines kinetic energy (EK) as the energy an object possesses due to its motion, and explains that kinetic energy can be calculated as EK = 1/2 mv^2, where m is the object's mass and v is its velocity.
2) It discusses the relationship between an object's maximum kinetic energy (EKmax) and its maximum velocity (vmax), explaining that EKmax occurs when an object's velocity is at its highest point (vmax).
3) It provides an example calculation of converting between units of kinetic energy, showing how to convert from joules to electron
SchoolDD.com provides concise explanations of trigonometric concepts like sine, cosine, and tangent functions. It explains how to use trigonometric functions to solve problems involving right triangles, with examples calculating values for angles like 30°, 60°, 37°, and 53° degrees. The site also summarizes trigonometric identity formulas and relationships between sine, cosine, and tangent for various angles.
1. The document discusses projectile motion and provides equations to calculate the time, height, horizontal displacement, and velocity of a projectile over time given the initial velocity and angle of launch.
2. Formulas are derived for calculating time, maximum height, and horizontal displacement of a projectile based on the initial velocity components along x and y axes.
3. Examples are provided to demonstrate how to apply the equations to different launch angles like 45 degrees, 60 degrees, and 30 degrees.
This document provides a concise summary of key scientific concepts and formulas in fewer than 3 sentences. It begins by defining common scientific units used to measure length, mass, time, electric current, temperature, amount of substance, and luminous intensity. It then explains the International System of Prefixes used to modify unit symbols and provides examples of their use. The document proceeds to demonstrate the application of scientific concepts and formulas to solve problems involving length, area, volume, speed, time period, percentage error, and other topics. Diagrams are included to illustrate geometric and trigonometric relationships. Key formulas from algebra, trigonometry, logarithms, and other areas are also summarized concisely.
The document summarizes key concepts about electricity and electrical circuits. It discusses:
1. Direct current (DC) and alternating current (AC), defining their characteristics.
2. Transformers, explaining how they work to change voltage and current levels in circuits using electromagnetic induction.
3. Electrical power calculations, defining formulas for power, voltage, current and resistance.
4. Characteristics of alternating current, including definitions of peak, root mean square and average values of voltage, current and power.
The document provides concise explanations of important electrical concepts with relevant formulas and examples.
The document summarizes key concepts about electricity and electrical circuits. It discusses:
1) Direct current (DC) and alternating current (AC), explaining the difference between constant and varying current over time.
2) Transformers, describing how they work by electromagnetic induction to change voltage and current levels while transmitting power.
3) Circuit parameters like voltage, current, resistance and power in AC circuits. Formulas are given relating peak, RMS and average values.
4) Waveforms of voltage, current and power over time in an AC circuit, showing their sinusoidal variation and phase relationship.
In 3 sentences or less, the document provides an overview of basic electrical concepts like different current types, transformer
The document provides tips and information about radioactive decay and half-life calculations in 3 sections. It defines key concepts like activity, half-life, and decay equations. Examples are given for common radioisotopes like Co-60 and I-131. Steps are outlined for calculations involving initial activity, remaining activity, and decay over time. Nuclear reactions and mass-energy equivalents are also briefly discussed.
This document discusses various topics relating to electromagnetic waves and radio communication technologies:
1. It describes the properties and characteristics of electromagnetic waves, including wavelength, frequency, and speed.
2. It explains different modulation techniques used in radio such as amplitude modulation (AM) and frequency modulation (FM). AM varies the amplitude of the carrier wave while FM varies the frequency.
3. It provides an overview of the electromagnetic spectrum, showing the range of wavelengths and frequencies used for communications technologies like radio and television broadcasting.
This document discusses electric current and concepts related to electricity. It contains the following key points:
1. Electric current is the flow of electric charge in a conductor. The direction of the flow is from higher electric potential to lower electric potential.
2. The factors that affect the magnitude of electric current include the amount of charge passing through a point in the conductor per unit time, and the resistance of the conductor.
3. Kirchhoff's laws relate the current and potential difference in different parts of an electric circuit.
1. Electric fields are produced by electric charges and can be calculated using Coulomb's law. Positive charges produce outward electric fields while negative charges produce inward electric fields.
2. The electric field strength is directly proportional to the magnitude of the charge producing the field and inversely proportional to the distance from that charge.
3. Electric potential difference is equal to the work done moving a test charge between two points in an electric field, and is calculated by multiplying the charge by the potential.
1. The document discusses the principles of refraction of light through spherical lenses and thin lenses. It defines terms such as focal length, focal point, radius of curvature, and refractive index.
2. Formulas are provided relating refractive index, angles of incidence and refraction, and focal lengths for different lens materials.
3. Worked examples apply the formulas to calculate focal lengths, refractive indices, angles of refraction and incidence, and image distances for various lens configurations and materials.
1. The document discusses concepts related to sound waves including frequency, wavelength, and speed of sound waves. It provides examples of calculating the speed of sound waves at different temperatures.
2. Formulas are given for calculating speed of sound waves based on temperature. The speed increases by 6 m/s as temperature rises from 25°C to 35°C, as shown through an example calculation.
3. Additional concepts covered include using the frequency and wavelength of a sound wave to calculate its speed, and examples of applying the concepts and formulas to solve problems.
1. The document discusses simple harmonic motion (SHM) and describes the sinusoidal function y=Asin(ωt) that models SHM.
2. Various examples of SHM are shown, including spring oscillations and waves on a string. The key parameters like amplitude, angular frequency, and period are defined.
3. Standing waves on a string are analyzed, with nodes and antinodes labeled according to the quantization condition that the string length must be an integer multiple of half wavelengths. Formulas for calculating wavelength and frequency are provided.
1. SchoolDD.com provides information about heat transfer and calorimetry. It explains key concepts like specific heat capacity, latent heat of fusion and vaporization, and uses equations like Q=mcΔT.
2. Examples are given to calculate the heat transfer involved in changing temperatures of substances. Specific heat values are provided for various materials at different phases.
3. Phase changes from solid to liquid to gas are explained, along with the concept of latent heat absorbed or released without changing temperature during these phase transitions.
This document discusses fluid dynamics and pressure. It defines density, pressure, and hydrostatic pressure. It provides examples of calculating hydrostatic pressure at different depths in fluids of varying densities. Formulas are given for calculating force, pressure, volume, and flow rate. Examples are worked through applying these formulas and concepts to problems involving submerged surfaces, fluids with different densities, and flow through pipes.
This document discusses concepts in mechanics including:
1. Conditions for static equilibrium, including that the net force and net torque must equal zero.
2. Analysis of forces in different mechanical systems using free body diagrams and applying Newton's laws and principles of torque.
3. Problem solving techniques for calculating unknown forces, torques or accelerations given force diagrams and relevant equations of motion.
This document discusses concepts related to rotational kinematics and dynamics including:
1. Rotational kinematics equations relating angular displacement (θ), angular velocity (ω), angular acceleration (α), and time (t).
2. Rotational dynamics equations relating torque (τ), moment of inertia (I), angular acceleration (α), and angular velocity (ω).
3. Examples calculating values like angular velocity, angular acceleration, linear velocity, torque, power, work, and kinetic energy for rotating objects using the rotational kinematics and dynamics equations.
1. O documento apresenta exemplos de cálculos de momento linear e impulso para sistemas de uma e duas partículas.
2. São resolvidos problemas envolvendo colisões elásticas e inelásticas entre partículas, calculando velocidades iniciais e finais a partir da conservação do momento linear.
3. Introduz conceitos como força, massa, velocidade, tempo de interação e coeficientes de atrito para analisar situações dinâmicas de um corpo sob ação de forças.
The document summarizes concepts related to forces and motion. It defines key terms like work, kinetic energy, and potential energy. It provides formulas for calculating work, kinetic energy, and gravitational potential energy. Examples are given to demonstrate applying the concepts and formulas to solve physics problems involving changes in kinetic and potential energy.
The document summarizes key concepts about electricity and electrical circuits. It discusses:
1. Direct current (DC) and alternating current (AC), defining their characteristics.
2. Transformers, explaining how they work to change voltage and current levels in circuits using electromagnetic induction.
3. Electrical power calculations, defining formulas for power, voltage, current and resistance.
4. Characteristics of alternating current, including definitions of peak, root mean square and average values of voltage, current and power.
The document provides concise explanations of important electrical concepts with relevant formulas and examples.
The document summarizes key concepts about electricity and electrical circuits. It discusses:
1) Direct current (DC) and alternating current (AC), explaining the difference between constant and varying current over time.
2) Transformers, describing how they work by electromagnetic induction to change voltage and current levels while transmitting power.
3) Circuit parameters like voltage, current, resistance and power in AC circuits. Formulas are given relating peak, RMS and average values.
4) Waveforms of voltage, current and power over time in an AC circuit, showing their sinusoidal variation and phase relationship.
In 3 sentences or less, the document provides an overview of basic electrical concepts like different current types, transformer
The document provides tips and information about radioactive decay and half-life calculations in 3 sections. It defines key concepts like activity, half-life, and decay equations. Examples are given for common radioisotopes like Co-60 and I-131. Steps are outlined for calculations involving initial activity, remaining activity, and decay over time. Nuclear reactions and mass-energy equivalents are also briefly discussed.
This document discusses various topics relating to electromagnetic waves and radio communication technologies:
1. It describes the properties and characteristics of electromagnetic waves, including wavelength, frequency, and speed.
2. It explains different modulation techniques used in radio such as amplitude modulation (AM) and frequency modulation (FM). AM varies the amplitude of the carrier wave while FM varies the frequency.
3. It provides an overview of the electromagnetic spectrum, showing the range of wavelengths and frequencies used for communications technologies like radio and television broadcasting.
This document discusses electric current and concepts related to electricity. It contains the following key points:
1. Electric current is the flow of electric charge in a conductor. The direction of the flow is from higher electric potential to lower electric potential.
2. The factors that affect the magnitude of electric current include the amount of charge passing through a point in the conductor per unit time, and the resistance of the conductor.
3. Kirchhoff's laws relate the current and potential difference in different parts of an electric circuit.
1. Electric fields are produced by electric charges and can be calculated using Coulomb's law. Positive charges produce outward electric fields while negative charges produce inward electric fields.
2. The electric field strength is directly proportional to the magnitude of the charge producing the field and inversely proportional to the distance from that charge.
3. Electric potential difference is equal to the work done moving a test charge between two points in an electric field, and is calculated by multiplying the charge by the potential.
1. The document discusses the principles of refraction of light through spherical lenses and thin lenses. It defines terms such as focal length, focal point, radius of curvature, and refractive index.
2. Formulas are provided relating refractive index, angles of incidence and refraction, and focal lengths for different lens materials.
3. Worked examples apply the formulas to calculate focal lengths, refractive indices, angles of refraction and incidence, and image distances for various lens configurations and materials.
1. The document discusses concepts related to sound waves including frequency, wavelength, and speed of sound waves. It provides examples of calculating the speed of sound waves at different temperatures.
2. Formulas are given for calculating speed of sound waves based on temperature. The speed increases by 6 m/s as temperature rises from 25°C to 35°C, as shown through an example calculation.
3. Additional concepts covered include using the frequency and wavelength of a sound wave to calculate its speed, and examples of applying the concepts and formulas to solve problems.
1. The document discusses simple harmonic motion (SHM) and describes the sinusoidal function y=Asin(ωt) that models SHM.
2. Various examples of SHM are shown, including spring oscillations and waves on a string. The key parameters like amplitude, angular frequency, and period are defined.
3. Standing waves on a string are analyzed, with nodes and antinodes labeled according to the quantization condition that the string length must be an integer multiple of half wavelengths. Formulas for calculating wavelength and frequency are provided.
1. SchoolDD.com provides information about heat transfer and calorimetry. It explains key concepts like specific heat capacity, latent heat of fusion and vaporization, and uses equations like Q=mcΔT.
2. Examples are given to calculate the heat transfer involved in changing temperatures of substances. Specific heat values are provided for various materials at different phases.
3. Phase changes from solid to liquid to gas are explained, along with the concept of latent heat absorbed or released without changing temperature during these phase transitions.
This document discusses fluid dynamics and pressure. It defines density, pressure, and hydrostatic pressure. It provides examples of calculating hydrostatic pressure at different depths in fluids of varying densities. Formulas are given for calculating force, pressure, volume, and flow rate. Examples are worked through applying these formulas and concepts to problems involving submerged surfaces, fluids with different densities, and flow through pipes.
This document discusses concepts in mechanics including:
1. Conditions for static equilibrium, including that the net force and net torque must equal zero.
2. Analysis of forces in different mechanical systems using free body diagrams and applying Newton's laws and principles of torque.
3. Problem solving techniques for calculating unknown forces, torques or accelerations given force diagrams and relevant equations of motion.
This document discusses concepts related to rotational kinematics and dynamics including:
1. Rotational kinematics equations relating angular displacement (θ), angular velocity (ω), angular acceleration (α), and time (t).
2. Rotational dynamics equations relating torque (τ), moment of inertia (I), angular acceleration (α), and angular velocity (ω).
3. Examples calculating values like angular velocity, angular acceleration, linear velocity, torque, power, work, and kinetic energy for rotating objects using the rotational kinematics and dynamics equations.
1. O documento apresenta exemplos de cálculos de momento linear e impulso para sistemas de uma e duas partículas.
2. São resolvidos problemas envolvendo colisões elásticas e inelásticas entre partículas, calculando velocidades iniciais e finais a partir da conservação do momento linear.
3. Introduz conceitos como força, massa, velocidade, tempo de interação e coeficientes de atrito para analisar situações dinâmicas de um corpo sob ação de forças.
The document summarizes concepts related to forces and motion. It defines key terms like work, kinetic energy, and potential energy. It provides formulas for calculating work, kinetic energy, and gravitational potential energy. Examples are given to demonstrate applying the concepts and formulas to solve physics problems involving changes in kinetic and potential energy.
2. 2
F F
F F FF F F
F F F F
F F F
F F F F F F
F F F F F F
F F F F F
F F F F
2.1 F
F F F F F
F F
1. F F F
F
F F F 1 2 F 1+2=3
1 . 2 . 3 .
+ =
2. F F F
FF F 2.2
F F F F F
F F
FA 5 F
5 .
– F F www.schoolDD.com 1
3. F F F 3 4 F
F 5 ( F F 3+4)
5N
4N
3N
F
- F F F F F F FF
F F
2.2 - F
F F F F F
F F F F F F
F F F F FF F F
F F F F F
F F F F
F F F F F 3 F F
F F FF F F F F
F F
F F =
– F F www.schoolDD.com 2
4. F F
F F F F F F F
R=
R= F F
=
A= F
B= F
= F F
F
F
.
2 3
-
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2+3=5 3-2=1
.
= +
3 3
=
2
2
F
- F F F F
- . F F F F F F F
F - F
F F F ( - = + (- ))
- F F . F F F
F F , , , F F F F F
– F F www.schoolDD.com 3
5. = ? , = ?
( ) + ( )=( )+( )?
2.3
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F F F F
F
s1, t1
s1
s2, t2
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s2
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F F F F F 3 F s1 , s2 s3 FF
F s1, s2 s3
F s2
1. s F F
F F F F F (m)
2. F
F F (m)
F
3. v F F F F
F (m/s)
v=
F 2
1. vt F F F
– F F www.schoolDD.com 4
6. F
vt = F
= ,
2. vav F F F
vav =
F
4. F F F F
F F (m/s)
=
F 2
1. t F F
F
t = F F
2. av FF F
F
F
av = F F
5. F F F
2
F F (m/s2 )
=
F F 2
1. F t F
F . F F
– F F www.schoolDD.com 5
7. F
t = F
2. F av F
F
av =
F
- F a= = v2 > v 1 F F F F
v2 < v 1 F F F ...
(v2 > v1) a +
(v2 < v1) a -( F F )
(v2 = v1) a 0
F
F F +, - 0
F F F ( F -)
F F F ?
F F F 0.5 m/s F F F
F F F ?
F 1
A C F B
C
50 m s = AB + BC
30 m = 40 + 30
A B = 70 m Ans
40 m = AC
= 50 m A C Ans
F F F
– F F www.schoolDD.com 6
8. F 2
P Q F 10
.
.
P 140 m Q .
.
. P
F 20
F
F s
π
. = = x = 220 m. Ans
. = PQ = 140 m. P Q Ans
. vav = = = 22 m/s Ans
. av = = = 14 m/s P Q Ans
. av = = = 0 m/s Ans
F 3
F F 4 m/s F 80 m. F F 10 m/s
F 50 m.
F F F
vav = ?
v1 = 4 m/s v2= 10 m/s
av = ?
s1 = 80 m s2 = 50 m
v = 4 m/s v =4
F F F F vav = s /t s = s1 + s2 t F F F F F
– F F www.schoolDD.com 7
9. v = F t =
t1 = = = 20 s
t2 = = = 5s
vav = = = = = 5.20 m/s Ans
av = F
= = = 5.20 m/s Ans
F F FF F F
F
F 4
F 3 F F F F
v1 = 4 m/s vav = ?
v2= 10 m/s av = ?
s1 = 80 m
v =s24 =m/s m
50
v =4
vav = = = = = 5.20 m/s
vav = 5.20 m/s F F F Ans
F av = F
av = = = 2.0 m/s F F F
F F F Ans
F
- F F F F F
F F F F F F FF
FFF F F F
– F F www.schoolDD.com 8
10. 2.4
F F F
F
t0 t1 t2 t3 t4 t5 t6
••• • • • • • •
s1
s2
s3
s4
s5
s6
50 F F F 1/50
F t0 - t2 v0 2 = = t1
F t1 - t5 v1 5 =
t3 v3 =
F F t2 - t5 a2 5 =
F t3 a3 = = F F t2 t4
50 F 100 F F F F
F ?
F F F ?
– F F www.schoolDD.com 9
11. F 5
F F F 4/50
F s1 = 1.0 cm , s2 = 2.2 cm , s3 = 3.6 cm , s444 = 5.2 cm , s5 = 7.0 cm s6 = 9.0 cm
50 F
F t = F
F
a4 = -------(1)
v3 = = (5.2 - 2.2) x 10-2 )/( ) = 0.75 m/s
v5 = = (9.0 - 5.2) x 10-2 )/( ) = 0.95 m/s
F v3 v5 (1)
F a4 =
=
a4 = 5 m/s2 Ans
F
F
• • • • • • - ( )
-
F
- F F
F
•• • • • • - ( ) F
-
F
- F ( +)
F
• • • • • • - ( ) F
-
F
- F ( -)
– F F www.schoolDD.com 10
12. 2.5 F F () () F () (t)
F F F F F F
F F F F
F F FF F F F F F
F F F F F F F F F
y
y = mx + c
y
c x
x
F y = mx + c
m (Slope) F F
c y
() (t)
= =
= t
y = mx + c F
F () (t) F (slope) F ()
F 0 (c = 0)
= t
→ → F =0
t
3
→ → F ( +)
2
1 t
– F F www.schoolDD.com 11
13. 3
2
→ → F ( -)
1
t
() (t)
F = =
= t
y = mx + c F
F () (t) F (slope) F F ()
= t
→ F
.= F .t =
t
F
- F F F
F F F y = mx + c F
F y,m,x F y x
m F
- F F
F F F F F F F F F
F F F
F F F F F F F
– F F www.schoolDD.com 12
14. F 6
(m)
. 50
20 . 50
. 5 , 20 35
0 t (s)
10 20 30 40 50 . 50
-10 . 50
. (s)
F F F F
t = 45 t=0 t = 10 → 30 +
F F t=0
s1 = 20
F 10 F 20 m F t = 10-30
s3 = 10 s2 = 20 F 20 m F F t = 30-40
t = 40 F F F F t
s4 = 10 = 40 F F F F F
t = 50
F F t = 45 F
- + -10 m F F F t = 50
=0( F F )
s = s1 + s2 + s3 + s4 ( F )
= 20 + 20 + 10 + 10 = 60 m Ans
. () 50
=0 F F F ( F ) Ans
. 5 , 20 35
t F t
( = = t y = mx + c F = m)
t=5s = (20 - 0)/(10 - 0) = 2 m/s Ans
t = 20 s = 0 m/s Ans
t = 35 s = (0 - 20)/(40 - 30) = -2 m/s ( F ) Ans
– F F www.schoolDD.com 13
15. . (vav)
F
=
F
vav =
vav = = 1.2 m./s Ans
. ( av)
F
=
F
av = F
= 0 m/s Ans
F 7
F () (t) F
(m/s)
. F
. F
20 .
15
s3 .
s2 s4
t (s) . F 1 7
0 s1 2 4 6 8
-15
t=2 s t=0
1
s2 s3 s4 F
t=4 t=6 t=8
. F s
F F F F F
s= F ( F )
F F F F
s = s1 + s2 + s3 +s4
= (½ x 2 x 15) + (½ x 2 x 15) + (½ x (20 + 15) x 2) + (½ x 2 x 20)
– F F www.schoolDD.com 14
16. s = 85 m Ans
. F
= F t( )
= s1 + s2 + s3 + s4
= - 15 + 15 + 35 + 20
= 55 m Ans
. vav
vav =
=
vav = 10.62 m/s Ans
. av
av = F
av =
av = 6.8 m/s Ans
. F 1 7 1 , 7
F = t( = )
∆
∆
= (0 (-15))/(2-0) = 7.5 m/s2 Ans
∆
t = 1s = 1 =
∆
∆
t = 7s = 7 =
∆
= (0 20)/(8-6) = -10 m/s Ans
2.6 F F a
F F F
F F F F F F F F F F F
F F F
F F F F F F
u t v
s
– F F www.schoolDD.com 15
17. F u / F t
v / F s
F
F a= =
F at = v u v = u + at ---(1)
v F v t F F
v = at + u v = u + at
v
v = at + u
u
y = mx + c
t
t
. F v t s s= ---(2)
F v = u + at (2)
F s=
s = ut + ½ at2 ---(3)
F t= (2)
F s=
2as = v2 u2
v2 = u2 + 2as ---(4)
4
u a( )
v
1. v = u + at
t
2. s = t
3. s = ut + ½ at2 s
4. v2 = u2 + 2as
F FF
F F t
t = F t=0
u = F
v =
s = F
a = F F ( + v>u - v<u F )
F F F F s = vt
– F F www.schoolDD.com 16
18. F FF F = F
F F F F s,u,v,a
F 8
F F 2 m/s2 F 5
F F F
a = 2 m/s2 F F F F
u=0 v=? F F F F F F F F F F
t = 5s F F FF F F ? F
F a = 2, t = 5, u = 0
s=? F F F F v = ?, s
=? F F 4 F F
Fu,a,t v F v = u + at
v = 0 + 2x5
v = 10 m/s Ans
s F s = t
s = (0 + 10 )/2 x 5
s = 25 m Ans
s = ut + ½ at2
s = 0 + ½ x 2 x 52
s = 25 m/s Ans
v2 = u2 + 2as
102 = 0 + 2(2) s
s = 25 m Ans
– F F www.schoolDD.com 17
19. F
- F F F s F 2,3 4 F F
4 ( F F) F F
F F F F F F F F FFF F
F F F F
F 9
F F F 72 / F F
F 5 F F
a= ? F F F F F
u = 20 m/s v= 0 F F F FF F F
t= 5 s F F F F
F F F
s= ?
F F
F F F F F / F
2
/ F F
u = 72 km/hr = (72 x 103m)/(60 x 60 ) m/s
u = 20 m/s
Fu,v t a F v = u + at
F F F
0 = 20 + a(5)
F F
∴ a = -4.0 m/s2 Ans u = 20 v=0
Fu,v t s F s = t
= (20 + 0)/2 (5)
∴ s = 50 m Ans
– F F www.schoolDD.com 18
20. F 10
A B F F F B F A F
F 4 m/s2 6 m/s2 A F 100 m. F F F
F F
F F F
u=0 aA = 4
A
A tA
sB - sA = ? sA = 100
u=0 aB = 6 B
B
tB
sB
∴ F F tA = tB = t
t F A
s = ut + ½ at2
100 = 0 + ½ x 4 x t2
t2 = 50
t =5 s
B F sB
s = ut + ½ at2
sB = 0 + ½ x 6 x 50
sB = 150 m
∴ F F F
sB - sA = 150 - 100 = 50 m Ans
F
- F F F F F F !
– F F www.schoolDD.com 19
21. F 11
F F 150 5 F F
F F 5 F 100 F F
F F F
a1 = ? v a2 = 0
u= ? v
t1 = 5 t2 = 5
s1 = 150 s2 = 100
F
v s = vt v = s/t ( v , a2 = 0)
v = 100/5 = 20 m/s
F
F u s = t
F F 150 = (u + 20)/2 (5)
u = 40 m/s Ans
F a1 v = u + at
F F 20 = 40 + a1(5)
a1 = - 4 m/s2 Ans ( F )
2.7 F F F F
F F F F F
F F F F F F g
F 9.8 m/s2 F F FF F
F F F F F
F F F F F F
F F F
4 F 2.6 F F F F F a F F F F g
– F F www.schoolDD.com 20
22. v=0 F F 4
F a g = 9.8 m/s2 ( F
+u +s +u 10 m/s ) 2
g F F FF
+s
-s -g
+g F / F
-v F .. F
+v
F u F
u F
F F
F 12
F 80
. F F F
. F
. F t
F
Fs,u a t F s = ut + ½ at2
u =0 F F F 80 = 0 + ½ x 10 x t2
t2 = 16
s = 80 t =? a =g
80 t = 4.0 s Ans
v =?
v
F u,a t v F v = u + at
F F v = 0 + 10 x 4
v = 40 m/s Ans
– F F www.schoolDD.com 21
23. F 13
F F 60 F 20 m/s
. F F F
. F F
. F 1,2,4,5
.
v=0
+s +u = 20 m/s
F F F
-s
a=g
s = 60
. F t
Fs,u a t F s = ut + ½ at2
F F -60 = 20 t + ½ (-10) t2 (s a F u)
t2 - 4 t - 12 = 0
(t - 6)(t + 2) = 0
t = 6 , -2 ( F F F )
F
t = 6 s Ans
. smax
v=0
Fu,v a s F v2 = u2 + 2as
F F 0 = 202 + 2 (-10) smax (a F u)
smax = 20 m (s u) Ans
. F t = 1,2,4,5 s
Fu,t a F s s = ut + ½ at2
v = u + at
t = 1s
s = ut + ½ at2
– F F www.schoolDD.com 22
24. 2
s = 20(1) + ½ (-10) (1)
s = 15 m (s u F ) Ans
v = u + at
v = 20 + (-10) (1)
v = 10 m/s (v u) Ans
t =2s
s = ut + ½ at2
s = 20(2) + ½ (-10)(1)2
s = 20 m Ans
v = u + at
v = 20 + (-10) (2)
v = 0 m/s Ans
t = 4s
s = ut + ½ at2
s = 20(4) + ½ (-10)(4)2
s = 0 m F Ans
v = u + at
v = 20 + (-10) (4)
v = -20 m/s ( F u=v F F ) Ans
t = 5s
s = ut + ½ at2
s = 20(5) + ½ (-10) (5)2
s = -25 m F (s F u F F ) Ans
v = u + at
v = 20 + (-10) (5)
v = -30 m/s Ans
– F F www.schoolDD.com 23
25. .
F F t = 6s( )
v = u + at
v = 20 + (-10) (6)
v = -40 m/s Ans
4 a F ?
4 u,v,a s + , -?
F F F
F
F F
F F F ?
F
- F F F F F F F F
F
F
– F F www.schoolDD.com 24
26. 2.8 F
F F F F F F 0.5
F F F F F F F
F F F F F F
F F F F F
F F
F F
FF
F F
- F ( F )
- ( ) F
- F F F ( )
F
F = + (- F )
F 14
FA F 30 / FB F 40 /
F FB F FA
vA = 30 m/s -v F = -vA
m/s
v = vB
v
vB = 40 m/s
F
F
v F =
v F =
v F = 50 m/s
F FA FB F 50 m/s F Ans
F F F F
F
F F F F
– F F www.schoolDD.com 25