CLASS-IX
FORCES AND LAWS OF MOTION
WORKSHEET-L1
Sub-topics:: a) Balanced and Unbalanced force
b) Inertia
A. Pick the correct option:
- An unbalanced force acts on a body. The body
a) must remain at rest
b) must move with uniform velocity
c) must be accelerated
d) must move along a circle
- If a body is not accelerated,
a) no force acts on it
b) no unbalanced force acts on it
c) the resultant force is not zero
d) a single force acts on it
- If no force acts on a body, it will
a) get deshaped
b) move with increasing speed
c) either remain at rest or move in a straight line
d) break
- Which of the following has the largest inertia?
a) A pin
b) An inkpot
c) Your physics book
d) Your body
- The inertia of an object tends to cause the object
a) to increase its speed
b) to decrease its speed
c) to resist any change in its state of rest or motion
d) to decelerate due to friction
B. Short –Answer Questions
Q1. In a tug of war the rope does not move in any direction. Why?
Q2. Can balanced forces change the shape and size of a body?
Q3. It is easier to push an empty box than to push the box full of
books.Why?
books.Why?
Q4. Two balls of the same size but of different materials, rubber
and iron are kept on the smooth floor of a moving train. The
brakes are applied suddenly to stop the train. Will the balls
start rolling? If so, in which direction? Will they move with
the same speed?Give reasons for your answer.
and iron are kept on the smooth floor of a moving train. The
brakes are applied suddenly to stop the train. Will the balls
start rolling? If so, in which direction? Will they move with
the same speed?Give reasons for your answer.
Q5. A body at rest opposes the forces which try to move it.
What is this property called?
Q6. If a ball is moving on a frictionless horizontal surface and no
forces are applied on it, will its speed increase, decrease or
remain constant?
forces are applied on it, will its speed increase, decrease or
remain constant?
