Page 1 - Class IX-PHYSICS-CH-8- FORCE AND LAWS OF MOTION

SAI INTERNATIONAL SCHOOL

PHYSICS

COMPETENCY BASED QUESTIONS

CLASS -IX

Chapter: FORCE and LAWS OF MOTION

Objective Questions:
1. Water tanker filled up to two by three of its site is moving with uniform speed. On
sudden application of brakes the water in the tank would
a) Move backward
b) move forward.
c) be unaffected
d) rise upwards.
2. According to the third law of Motion ,action and reaction.
a). Always act on same body
b) always act on different body in opposite direction.
c) Have the same magnitude and direction.
d) Act on either body at normal to each other.
3. Which physical quantity is equal to the rate of change of momentum?
a) Impulse
b) energy
c) force
d) velocity.
4. A puck slides across a frictionless ice surface. What will happen to the puck
according to the Newton’s first law,
a) Gravity will eventually bring it to a stop.
b) It will continue moving indefinitely
c) It will slow down because of air resistance.
d) It will change direction at random.
5. Two ice skaters, one weighing 50Kg and the other 70Kg. Push off against each
other. If the lighter skater moves backward at 5 meter per second, what is the
velocity of heavier skater?
a) 3.57m/s
b) 2.50m/s
c) 7.14 m/s
d) 1.79m/s
6. A man pushes four boxes of different masses. The table shows the acceleration
produced for Each box during the push.

a) What amount of force does the man exert on each box? Show the calculation.