Law Of Conservation Of Energy - Practice Questions & MCQ

A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work (in Joule) done by the force of gravity during the time the particle goes up is :

A mass of M kg is suspended by a weightless string . The horizontal force that is required to displace it until the string making an angle of 45^o  with the initial vertical direction is

A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement  x is proportional to :

A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particle takes place in a plane. It follows that : 

Consider a rubber ball freely falling from a height onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then the velocity as a function of time and the height as function of time will be

The block of  mass M  moving on  the frictionless horizontal  surface collides with the spring of spring constant K  and compresses it by length L.The maximum  momentum of the block after collision is

A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m . It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is

Two hydrogen atoms are in excited state with electrons residing in n = 2. First one is moving towards left and emits a photon of energy  towards right. Second one is moving towards right with same speed and emits a photon of energy  towards right. Taking recoil of nucleus into account during emission process

The potential energy of a 1 kg particle free to move along the x-axis is given by

The total mechanical energy of the particle 2 J. Then, the maximum speed (in m/s) is :