What is the kinetic energy of a body of mass 50 kg after it has fallen from rest for 5 seconds? (g = `9.8 m/s^2`)

Calculate the gain in kinetic engery of a body of mass 10 kg after falling from rest for 2 seconds.

What is the expression for kinetic energy of a body of mass 'm' moving with velocity 'v'.

Give the magnitude and direction of the net force acting on a stone of mass 0.1 kg, (a) just after it is dropped from the window of a stationary train,(b) just after it is dropped from the window of a train running at a constant velocity of 36 km/h,just after it is dropped from the window of a train accelerating with 1 ms^2,just after it is dropped from the window of a train accelerating with 1M/S2

The blades of a windmill sweep out a circle of area A. (a) If the wind flows at a velocity v perpendicular to the circle, what is the mass of the air passing through it in time f?(b) What is the kinetic energy of the air? (c) Assume that the windmill converts 25% of the wind’s energy into electrical energy, and that A = 30 m^- 2 , v = 36 km/h and the density of air is 1.2 kg m^-3 . What is the electrical power produced?

A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m s^-1 to 3.5 m s^-1 in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?

If g is the acceleration due to gravity on the earth’s surface, the gain in the potential energy of an QBject of mass m raised from the surface of the earth to a height equal to the radius R of the earth is :

A player throws a bail upwards with an initial speed of 29.4 m s^-1 . To what height does the ball rise and after how long does the ball return to the player’s hands? (Take g = 9.8 m s-2 and. neglect air resistance).

The kinetic energy of an object of mass, m moving with a elocity of 5 ms^-1 , is 25J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

A solid cylinder of mass 20 kg rotates about its axis with angular speed 100 rad s-^1. The radius of the cylinder is 0.25 m. What is the kinetic energy associated with the rotation of the cylinder? What is the magnitude of angular momentum of the cylinder about its axis?