Physics Test 18...

An electric lift with a maximum load of 2000kg (lift + passengers) is moving up with a constant speed of 1.5ms⁻¹. The frictional force opposing the motion is 3000N. The minimum power delivered by the motor to the lift in watts is : (g=10ms⁻²)

The distance covered by a body of mass 5g having linear momentum 0.3kgm∕s in 5s is:

A particle is released from height S from the surface of the Earth. At a certain height its kinetic energy is three times its potential energy. The height from the surface of earth and the speed of the particle at that instant are respectively

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is

A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when

A moving block having mass m, collides with another stationary block having mass 4m. The lighter block comes to rest after collision. When the initial velocity of the lighter block is v, then the value of coefficient of restitution (e) will be

Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50ms⁻¹. Take 'g' constant with a value 10ms⁻². The work done by the

(i) gravitational force and the

(ii) resistive force of air is

Two identical balls A and B having velocities of 0.5ms⁻¹ and 0.3ms⁻¹ respectively collide elastically in one dimension. The velocities of B and A after the collision respectively will be

A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to 8×10⁻⁴J by the end of the second revolution after the beginning of the motion?

What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that can complete the loop?