Laws Of Motion

Physics
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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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Two identical ladders are arranged as shown in the figure. Mass of each ladder is and length . The system is in equilibrium. Find direction and magnitude of friction force acting at A or B.

A
horizontally outwards
B
 horizontally inwards
C
 horizontally outwards
D
None of these.
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The horizontal component and vertical component of the reaction at end P are given by:

A
B
C
D
Hard
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The tension in the string is:

A
N
B
N
C
N
D
N
Hard
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Which of the following statements for a rigid object undergoing pure translational motion are false?

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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