اختبار على درس work and energy

If the velocity of an object is doubled and its mass decreases to its quarter so , its kinetic energy……….

A van driver adjusts the force on the van’s brakes so that the van travels at constant speed down from the top of a hill to its bottom. The magnitude of the change in the van’s kinetic energy is KE and the magnitude of the change in the van’s potential energy is PE, so which statement is correct ?………

The kinetic energy of an object is 4 J. What is its kinetic energy if its speed is doubled ?……….

A body of mass 0.5 kg falls freely from rest . If its kinetic energy after time (t) is 256J, then the kinetic energy of the body after time (2 t) from the moment of its falling equals……….

The potential energy of an object of mass 1 kg at the surface of the earth equals ………

When an object is thrown upwards……..

Joule is equivalent to……..

When an object falls freely………

A perpendicular force of 40 N acts on a body that moves in a circular path to displace it 10 m, then the work done equals ……..

The work is negative if the direction of the displacement…………..direction of the force

The stored energy in a compressed spring is ……….

The work done is maximum when the angle between the direction of the force that acts on a body and the direction of its displacement equals……

Which does not constitute a change in work?………

Two bodies x and y have the same mass, if (KE)x = 4 (KE)y , then the momentum of x equals ………

A man went to this apartment twice ; once by using the stairs and another time by using the elevator . Which statement is correct?………

Two object , the mass of the first is doubled that of the second and the velocity of the first is half that of the second. So, the kinetic energy of the first is……… that of the second

An object of mass 2 Kg has a kinetic energy of 25 J , its velocity equals ………..m/s

A 4 kg cart has a linear momentum with a magnitude of 20 kg.m/s what is the cart’s kinetic energy ?………

A bullet penetrates a wooden block and loses half its velocity . What is the ratio between the initial kinetic energy of the bullet and the kinetic energy of the bullet when it leaves the block ?……..:

An object of mass 12 kg is falling freely from a certain height, if its mechanical energy at the mid-distance between its initial position and the ground is 150 J, then its speed at the instant of touching the ground =……. m/s

When an object is projected vertically upwards, which of the following physical quantities will equal zero at the maximum height ?………

A mother pushes her child’s cart with a constant velocity on a straight horizontal road by a force that makes with the horizontal an angle of 60° . If a friction force of 20 N acts on the cart, then the work done by the mother to move the cart a distance of 5 m equals ……..

When the speed of a car is doubled , its kinetic energy……….

When an object is thrown vertically upwards, its mechanical energy will…….

A particle rotates in a uniform circular path of radius 20 cm where a centripetal force of 10 N acts on it, so the particle’s kinetic energy is ………

The work done by the brakes is ………

The ratio between the mechanical energy of an object that is projected vertically upwards and its potential energy at maximum height is …….. one

An object of mass 2 kg is at a height of 5 m above the ground, so its potential energy equals…….. (knowing that : g = 9.8 m/s2)

For a particle moving in a vertical circle ………

If the force acting on a body is doubled such that the body covers the same displacement , then the work done ………