# Laws Of Motion

## Which of the following statements for a rigid object undergoing pure translational motion arefalse?

A
If an object receives an impulse its kinetic energy must change.
B
An object's kinetic energy can change without the object changing momentum.
C
An object can receive a net impulse without any work being done on it.
D
A force may do work on an object without delivering any change in momentum.
Hard
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## A very long uniform helix is made of thin metal wire. The axis of helix is vertical. A small bead begins to slide down the fixed helix starting from rest. Considering friction between bead and wire of helix to be non-zero, which of the following statements is/ are true as long as bead moves on helix.

A
The speed of bead keeps on increasing.
B
The magnitude of frictional force on bead remains constant.
C
The speed of bead first increases and then remains constant.
D
The magnitude of frictional force increases and then remains constant.
Hard
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