NEET Physics - New - Laws of Motion

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Question - 1

A body initially at rest and sliding along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB = D. The height h is equal to:

  • A 7/5 D
  • B D
  • C 3/2 D
  • D 5/4 D

Question - 2

Which one of the following statements is incorrect?

  • A Rolling friction is smaller than sliding friction
  • B Limiting value of static friction is directly proportional to normal reactions
  • C Frictional force opposes the relative motion
  • D Coefficient of sliding friction has dimensions of length

Question - 3

Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:

  • A g,\(\frac{g}{3}\)
  • B \(\frac{g}{3}\),g
  • C g,g
  • D \(\frac{g}{3}\),\(\frac{g}{3}\)

Question - 4

A rigid ball of mass m strikes a rigid wall at 60° and gets reflected without loss of speed as shown in the figure below. The value of impulse imparted by the wall on the ball will be

  • A \(\frac{mV}{2}\)
  • B \(\frac{mV}{3}\)
  • C mV
  • D 2mV

Question - 5

Two identical balls A and B having velocities of 0.5 m/s and - 0.3 m/s respectively collide elastically in one dimension. The velocities of B and A after the collision respectively will be :

  • A -0.3 m/s and 0.5 m/s
  • B 0.3 m/s and 0.5 m/s
  • C -0.5 m/s and 0.3 m/s
  • D 0.5 m/s and -0.3 m/s

Question - 6

Three blocks A, B and C, of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on
the 4 kg block, then the contact force between A and B is:

  • A 18 N
  • B 2 N
  • C 6 N
  • D 8 N

Question - 7

A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a horizontal position. The knives are at a distance d from each other. The center of mass of the rod is at distance x from A. The normal reaction on A is :

  • A \(\frac{W(d-x)}{x}\)
  • B \(\frac{Wx}{d}\)
  • C \(\frac{Wd}{x}\)
  • D \(\frac{W(d-x)}{d}\)

Question - 8

A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is :

  • A 2 mv2
  • B 4 mv2
  • C mv2
  • D \(\frac{3}{2}mv^{2}\)

Question - 9

The force 'F' acting on a particle of mass 'm' is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is :

  • A 12 Ns
  • B 6 Ns
  • C 24 Ns
  • D 20 Ns

Question - 10

A uniform force of \(3\hat{i}+\hat{j}\) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position \(2\hat{i}+\hat{k}\)  metre to position \(4\hat{i}+3\hat{j}-\hat{k}\)  metre. The work done by the force on the particle is:

  • A 9 J
  • B 6 J
  • C 13 J
  • D 15 J