PPT FOR SCIENCE 9

1. MC HILL BAREO
Teacher III
Uniformly
Accelerated Motion
Horizontal and Vertical dimension

2. Objectives
 A. differentiate speed, velocity and
acceleration
 B. solve worded problems on uniformly
accelerated motion horizontal dimension
 Practice safety and awareness in dealing
with high accelerating objects.

4. SPEED
THE RATE OF DISTANCE OVER TIME
(s=d/t)
Example:
An athlete covers 50 meters after 5
sec. What is its speed?

5. VELOCITY
THE RATE OF DISPLACEMENT OVER
TIME WITH RESPECT TO DIRECTION.
Example:
A car covered 250 meters after 6
sec. going north. What is it’s
velocity?

6. ACCELERATION
- a object’s capacity to gain speed within a
short time.
- the rate of change of velocity per unit of
time.
1. HORIZONTAL 2. VERTICAL

7. Velocity = m/s
Time = s
Acceleration = 𝑚/𝑠2
Distance = m

8. Uniformly Accelerated Motion:
1.Horizontal Dimension
If a body maintains a constant change in
its velocity in a given time interval along
straight line, then the body is said to have
a uniform acceleration.

9.  The change in an airplane’s position for each time
interval is increasing as shown in Figure 1, thus, it
is moving faster and faster. This means that the
plane is accelerating.

10. Key Equations/formulae
Equation D 𝑑 =
𝑣𝑓 + 𝑣𝑖
2
𝑡
Equation E 𝑑 = 𝑣𝑖𝑡 +
𝑎𝑡2
2
Equation F 𝑣𝑓
2
= 𝑣𝑖
2
+ 2𝑎𝑑

11. An athlete jogs at a speed of
5 m/s and suddenly
accelerates at 10 m/s as he
approaches a free runway.
What is the athlete’s average
velocity?

12. A horse runs at 45.6 m/s
before accelerating to 62
m/s in 6.8 seconds. What
is the horse’s acceleration?

13. A motorcycle runs at 55 m/s and
suddenly accelerates at 92 m/s. What
will be the distance reached by the
motorcycle inside 8.2 seconds?

14. A jeepney from rest accelerates
uniformly over a time of 3.25 s and
covers a distance of 15 m.
Determine the acceleration of the
jeepney.
Answer: 2.8 𝑚/𝑠2

15. An airplane from rest accelerates on a
runway at 5.5 𝑚/𝑠2
for 20.25 s until it
finally takes off the ground. What is the
distance covered before take off?

16. 1. A race car accelerates uniformly
from 18.5 m/s to 46.1 m/s in 2.47
seconds. Determine the
acceleration of the car and the
distance traveled.

17. An airplane from rest accelerates on a runway at
5.5 𝑚/𝑠2
for 20.25 s until it finally takes off the
ground. What is the distance covered before take
off?
Given: a =5.5 𝑚/𝑠2
Unknown: d
t = 20.25 s
𝑣𝑖 = 0 m/s
Solution:
𝑑 = 𝑣𝑖𝑡 +
𝑎𝑡2
2
𝑑 = (0𝑚/𝑠)(20.25𝑠) +
(5.5 𝑚/𝑠2)(20.25 𝑠)2
2
𝑑 =1,130 m

19. Answer the following problems.
1. A trains runs at 35 m/s and suddenly
speeds up to 100 m/s. What is the
average velocity of the train?
Answer: 67.5 m/s

20. ASSIGNMENT
1. A race car accelerates uniformly from 18.5 m/s
to 46.1 m/s in 2.47 seconds. Determine the
acceleration of the car and the distance
traveled.
2. Rocket-powered sleds are used to test the
human response to acceleration. If a rocket-
powered sled is accelerated to a speed of 444
m/s in 1.83 seconds, then what is the
acceleration and what is the distance that the
sled travels?

21. QUIZ:
Solve the following problems. Show a
complete solution for each problem
(5pts each)
1. A dog runs at 45.6 m/s
before accelerating to 62
m/s in 6.8 seconds. What is
the dog’s acceleration?

22. 2. An object runs at 35 m/s and
suddenly speeds up to 78 m/s. What is
the average velocity of the object?
3. A motorcycle from rest suddenly
accelerates at a rate of 45 m/s2. What
will be the distance reached by the
motorcycle after 7.2 seconds?

23. 4. A car from rest suddenly moves at a
velocity of 18 m/s . Determine the
acceleration of the car after it reached
a distance of 121 m.

25. 2. Vertical dimension
FREE FALL
Acceleration due to gravity in
our planet earth is -9.8 m/s2
It is constant/unchanging.

26. If an object jumps, rises,
thrown upwards, assume that
the HEIGHT IS POSITIVE (+).
If an object drops, falls down,
assume that the HEIGHT IS
NEGATIVE (-)

27. A kangaroo is capable of
jumping to a height of 2.62 m.
Determine the takeoff speed of
the kangaroo.

28. A stone is dropped into a deep
well and is heard to hit the
water 3.41 s after being
dropped. Determine the depth
of the well.

29. The observation deck of tall
skyscraper 370 m above the street.
Determine the time required for a
penny to free fall from the deck to
the street below

30. A feather is dropped on the moon from
a height of 1.40 meters. The
acceleration due to gravity on the
moon is -1.67 m/s2. Determine the
time for the feather to fall to the
surface of the moon.

31. Zed is playing with a ball of a
building but the ball fell and hits
the ground after 2.6 seconds. What
is the final velocity of the ball just
before it hits the ground?

32. A boy drops a pile of wood from the
top of a roof located 8.52 meters
above the ground. Determine the
time required for the pile of wood
to reach the ground.

33. A boy threw the ball vertically upwards
with an initial velocity of 8.3 m/s.
determine the height to which the ball
will rise above its initial height. Assume
that the final velocity is 0 m/s.

34. A ball is thrown upward at a velocity
of 3.5 m/s. what is the greatest
amount of time that must pass
after the ball is thrown, so that the
ball is 0.25 meters above its launch
point?

35. An object is thrown with an
initial upward velocity 0f 5
m/s. what is its velocity after
1.5 seconds?