A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to

A body is moving unidirectionally under the influence of a source of constant power. Its displacement in time t is proportional to

Equal masses (m each) are attached at the two ends of a string passing over two pulleys. Another mass is attached at the centre of the string. In order that there is no sag in the string, this mass should be

A heavy stone is thrown from a cliff of height h with a speed v. The stone will hit the ground with maximum speed if it is thrown

The work done by the external forces on a system equals the change in

What is the coefficient of restitution?

If the momentum and total energy is conserved, then define the collision is occurred?

Is the total linear momentum conserved during the short time of an elastic of two balls?

In a game of tug of war , one team is slowly giving way to the other.Which team is doing positive work and which team nagative?

Calculate the power of a motor which is capable of raising of water in 5 min from a well 120 m deep.

Find the work done in pulling and pushing a roller through 100 m horizontally when a force of 1500 N is acting a chain making an angle of 60⁰ with  ground. Assume the floor to be smooth .

Can kinetic energy of a body be negative? Can potential energy be negative?

What is the nature of force involved in the winding of a watch?

A block of mass 1.2 kg moving at a speed of 20cm/s collides head-on with a similar block kept at rest. The coefficient of restitution is 3/5, find the loss of kinetic energy during collision.

When a 300 g mass is hung from a vertical spring, it stretches from equilibrium by 10 cm.What work is required to stretch it by next 5 cm?

A body of mass 2kg is at rest at a height of 10 m above the ground. Calculate its potential energy and kinetic energy after it has fallen through half the height. Also find the velocity at this instant.

To simulate car accidents, auto manufacturers study the collisions of moving cars with mounted springs of different spring constants. Consider a typical simulation with a car of mass 1000 kg moving with a speed 18.0 km/h on a smooth road and colliding with a horizontally mounted spring of spring constant 5.25 × 10 3 N m^–1 . What is the maximum compression of the spring ?

State if each of the following staement is true or false. Give reasons for your answer.
(i) Total energy of a system is always conserved, no matter what internal and external forces on the body are present?
(ii) Work done in the motion of a body over a closed loop is zero for every force in nature.
(iii) In an inelastic collision, the final kinetic energy is always less than the initial kinetic energy of the system.

A block of mass M is pulled along a horizontal surface by applying a force at an angle \(\theta\) with horizontal. Coefficient of friction between block and surface is \(\mu\). If the block travels with uniform velocity, find the work done by this applied force during a displacement d of the block.