# Laws Of Motion

## In which of the following cases the net force is not equal to zero?

A
A kite skillfully held stationary in the sky.
B
A ball falling freely from a height.
C
A helicopter hovering above the ground.
D
A cork floating on the surface of water.
View Solution ## Maximum value of static friction is:

A
limiting friction
B
rolling friction
C
normal friction
D
coefficient of static friction
View Solution ## Impulse is equal to

A
momentum
B
change in momentum
C
rate of change of momentum
D
rate of change of force
View Solution ## A certain particle undergoes erratic motion. At every point in its motion, the direction of the particle's momentum is always

A
the same as the direction of its velocity
B
the same as the direction of its acceleration
C
the same as the direction of its net force
D
the same as the direction of its kinetic energy
View Solution ## A stone tied to a string is rotated in a vertical circle. The minimum speed with which the stone has to be rotated in order to complete the circle :

A
decreases with increasing the mass of the stone
B
is independent of the mass of the stone
C
decreases with increasing the length of the string
D
is independent of the length of the string
View Solution ## Which of following Newton's laws reveals the underlying symmetry in the forces that occur in nature?

A
First law
B
Second law
C
Third law
D
Law of gravitation
View Solution ## The quantity that best represents the motion of a rigid body is

A
its mass.
B
its speed.
C
its velocity.
D
its linear momentum.
View Solution ## Statement A: If the force varies with time then the net force is measured by the total change in momentum of the body. Statement B: Change in momentum and impulsive force are numerically equal.

A
A & B are correct
B
A & B are wrong
C
A is correct and B is wrong
D
A is wrong and B is correct
View Solution ## When a moving body is suddenly stopped, then:

A
Frictional force increases.
B
Friction force remains same as it was while the car was moving.
C
Friction force reduces but has a non zero value.
D
Frictional force reduces to zero as it is a self adjusting force.
View Solution 