1. Define acceleration and state its SI unit.
For motion along
a straight line, when do we consider the acceleration to be
() positive (ii) negative? Give an example of a body in
uniform acceleration.
2. Find the total displacement of the body from the
following graph:
20
15
10 D
B
5
2 8 10
10
t(s)
3. A car travels at 54 km/h for first 20 s, 36 km/h for next 30
s and finally 18 km/h for next 10 s. Find its average speed.
4. Define acceleration and give its SI unit. When is
acceleration of a body negative? Give two examples of
situations in which acceleration of the body is negative.
5. Distinguish between uniform motion and non, uniform
motion. Is uniformly accelerated motion uniform motion?
Give one example each of uniform and non-uniform motion.
6. The speedometer readings of a car are shown below.
Find the acceleration of the car and its displacement.
Time Speedometer
9:25am 36 km/h
9:45 am 72 km/h
7. Define uniform circular motion and give example of it.
Why is it called accelerated motion?
1. State two effects of force.
2. Scientist who first conducted experiment to form
the base for Newton's first law of motion.
3. If first law of motion holds true, why does a ball
rolling on ground stop on its own?
4. What would happen if there was no friction on the
Earth?
5. What would happen if gravitational force of the
Sun suddenly vanishes?
6. What did Galileo observe by placing two inclined
planes facing each other and rolling down a marble
ball from top end of one of them?
7. What is the negative effect of friction on your
shoe soles?
8. You are applying force on the pan of single pan
weighing balance and the pointer points to 100 g.
What is the force in newtons applied by you?
9. An athlete always runs some distance before
taking a jump. Why?
10. A cricket ball of mass 70g moving with a
velocity of 0.5 m/s is stopped by a player in 0.5 s.
What is the force applied by the player to stop the
ball?
11. In a cricket match, why does a player lower his
hands slightly while catching the ball?
12. Two cars having masses in the ratio 4:5,
accelerate in the ratio 2:3. Find the ratio o forces
exerted by each of them.
