MEDIUM
Earn 100

A block of mass  m is placed on a frictionless inclined plane of angle θ. What  is the acceleration of the block when it is released? Calculate the time taken by the block to reach the bottom and its speed at the bottom.

Question Image

 

 

Important Questions on Laws of Motion

MEDIUM

A steel block of 10 kg rests on a horizontal floor as shown. When three iron cylinders are placed on it as shown, the block and cylinders go down with an acceleration 0.2 m s-2. The normal reaction R' by the floor if mass of the iron cylinders are equal and of 20 kg each is in N,

[Take g=10 m s-2 and μs=0.2

Question Image

MEDIUM

Two blocks A and B of masses 1.5 kg and 0.5 kg respectively are connected by a massless inextensible string passing over a frictionless pulley as shown in the figure. Block A is lifted until block B touches the ground and then block A is released. The initial height of block A is 80 cm when block B just touches the ground. The maximum height reached by block B from the ground after the block A falls on the ground is

Question Image

MEDIUM

A boy of mass 4 kg is standing on a piece of wood having mass 5 kg. If the coefficient of friction between the wood and the floor is 0.5 , the maximum force that the boy can exert on the rope so that the piece of wood does not move from its place is _______ N. (Round off to the Nearest Integer)

[Take g=10 m s-2

Question Image

EASY

An object of mass m is being moved with a constant velocity under the action of an applied force of 2 N along a frictionless surface with following surface profile.

Question Image

The correct applied force vs distance graph will be :

MEDIUM

Calculate the acceleration of the block and trolly system shown in the figure. The coefficient of kinetic friction between the trolly and the surface is 0.05. (g=10 m s-2, mass of the string is negligible and no other friction exists).

Question Image

MEDIUM

A block of mass m slides on the wooden wedge, which in turn slides backward on the horizontal surface. The acceleration of the block with respect to the wedge is:
Given m=8 kg, M=16 kg
Assume all the surfaces shown in the figure to be frictionless.

Question Image

MEDIUM

An inclined plane making an angle of 30° with the horizontal is placed in a uniform horizontal electric field 200NC as shown in the figure. A body of mass 1 kg and charge 5 mC is allowed to slide down from rest at a height of 1 m. If the coefficient of friction is 0.2, find the time taken by the body to reach the bottom.
g=9.8 m s-2; sin30°=12; cos30°=32

Question Image

MEDIUM

Two bodies A and B of masses 5 kg and 8 kg are suspended from a rigid support by inextensible massless strings as shown in figure. If the whole system is accelerated upwards at 2 ms-2, the tension in each string is g=10 ms-2

Question Image

MEDIUM
An object takes n times as much time to slide down a 45° rough inclined plane as it takes to slide down a perfectly smooth 45° inclined plane. The coefficient of kinetic friction between the rough plane and the object is
MEDIUM
Two blocks of masses m1 and m2 are suspended by a massless string passing over a smooth pulley. If the acceleration of the system is g8,then the ratio of the masses m2 m1=
HARD
When a body slides down from rest along a smooth inclined plane making an angle of 30° with the horizontal, it takes time T. When the same body slides down from the rest along a rough inclined plane making the same angle and through the same distance, it takes time αT, where α is a constant greater than 1. The co-efficient of friction between the body and the rough plane is 1xα2-1α2 where x=__________.
EASY
Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity g is:
Question Image
EASY
Consider two masses m1 and m2 are connected through a pulley. Mass ' m2 ' stats from rest at height ' h ' and falls down. With what speed it hits the ground? (Assume no friction and massless strings & pulleys)
Question Image
MEDIUM
Two masses m1 and m2 are connected by a massless string over a fixed pulley. If m1>m2m1 will move downward and m2 will move upward. What is the acceleration with which the combination of two masses will move? (g= acceleration due to gravity)
MEDIUM

The boxes of masses 2 kg and 8 kg are connected by a massless string passing over smooth pulleys. Calculate the time taken by box of mass 8 kg to strike the ground starting from rest.  g=10 m s-2 

Question Image

MEDIUM

A block of mass 40 kg slides over a surface, when a mass of 4 kg is suspended through an inextensible massless string passing over frictionless pulley as shown below.
The coefficient of kinetic friction between the surface and block is 0.02. The acceleration of block is: (Given g=10 m s-2.)

Question Image

MEDIUM

In the arrangement shown in figure a1,a2,a3 anda 4   are the accelerations of masses m1,m2,m3 and m4 respectively. Which of the following relation is true for this arrangement?

Question Image

EASY
A block of mass 48 kg kept on a smooth horizontal surface is pulled by a rope of length 4 m by a horizontal force of 25 N applied to the other end. If the linear density of the rope is 0.5 kg m-1, the force acting on the block is
HARD

A student skates up a ramp that makes an angle 30° with the horizontal. He/she starts (as shown in the figure) at the bottom of the ramp with speed v0 and wants to turn around over a semicircular path xyz of radius R during which he/she reaches a maximum height h (at point y) from the ground as shown in the figure. Assume that the energy loss is negligible and the force required for this turn at the highest point is provided by his/her weight only. Then (g is the acceleration due to gravity)

Question Image

HARD

The machine as shown has 2 rods of length 1 m connected by a pivot at the top. The end of one rod is connected to the floor by a stationary pivot and the end of the other rod has roller that rolls along the floor in a slot. As the roller goes back and forth, a 2 kg weight moves up and down. If the roller is moving towards right at a constant speed, the weight moves up with a :

Question Image