3. SPEED
Distance covered by an object in a
unit time is called speed of the
object.
Ex. If a car is moving with a speed of
50 K.M /h it implies that it will cover
a distance of 50 K.M.in one hour.
Speed =Total distance covered
----------------------------
total time taken
4. MOTION-NON UNIFORM MOTION
If the speed of the object moving
along a straight line keeps changing
,its motion is said to be non uniform
motion.
5. MOTION-UNIFORM MOTION
If the speed of the object moving
along a straight line with a constant
speed, its motion is said to be
uniform motion.
6. Measurement of time
We measure the intervals of time .
Ex.
1.The time interval between one sun
raise and the next was called day.
2. A year was fixed as the time taken by
the earth to complete one rotation.
7. Measurement of time
Periodic events are used for the
measurement of time
Periodic motion of the pendulum has
been used to make clocks and
watches.
Well known periodic motion is that of
simple pendulum.
8. SIMPLE PENDULUM
The pendulum completes one oscillation when bob
moves one extreme position `A’ to the other extreme
potion `B’ and come back to `A’.
The time taken by the pendulum to complete one
oscillation is called time period.
The time taken by the pendulum to complete one
oscillation is called time period.
If the time period is one second it is called seconds
pendulum. pendulum clocks are developed on this
principle
10. SIMPLE PENDULUM
The time taken by
the pendulum to
complete one
oscillation is called
time period.
If the time period
is one second it is
called seconds
pendulum.
pendulum clocks
are developed on
this principle
11. Quartz watches
Now a days most of the clocks or
watches have an electric circuit with
one or more cells. These clocks are
called quartz watches.
12. UNITS OF TIME AND SPEED
BASIC UNIT OF TIME IS –SECOND
BASIC UNIT OF SPEED
=DISTANCE/TIME. m/S.
13. MEASUREMENT OF SPEED
Speed is measured with the help of
speedometer.It records the speed
directly in km/h.
14. MEASUREMENT OF DISTANCE
Another meter which measures the
distance moved by the vehicle . This
is known as ODOMETER
15. DISTANCE AND TIME GRAPH
Motion of the objects can be
presented in pictorial form by their
distance and time graph
16. DISTANCE AND TIME GRAPH
The distance and time graph for the
motion of an object moving with
constant speed is straight line.
17. DISTANCE AND TIME GRAPH
With the help of distance and time
graph we can find the speed of the
bus at a particular time or the
distance traveled by the vehicle at a
particular time.