A body of mass m is hauled from the Earth's surface by applying a force F varying with the height of ascent y as F=2(ay-1)mg, where a is a positive constant.The work performed by this force in the gravitational field of the Earth over the first half of the ascent is

A body of mass m was slowly hauled up the hill as shown in the fig. by a force F which at each point was directed along a tangent to the trajectory. Find the work performed by this force, if the height of the hill is h, the length of its base is I and the coefficient ot friction is mu . .

A body of mass m was slowly pulled up the hill by a force F which at each point was directed along the tangent of the trajectory. All surfaces aresmooth. Find the work performed by this force.

A block of mass m is taken from A to B under the action of a constant force F. Work done by this force is

If a body of mass m is raised to height 2 R from the earth s surface, then the change in potential energy of the body is (R is the radius of earth)

A body of mass m is placed on the earth's surface . It is taken from the earth's surface to a height h = 3 R where R is the radius of the earth. The change in gravitational potential energy of the body is

A body of mass m is moving in a circle of radius r with a constant speed v. The work done by the centripetal force in moving the body over half the circumference of the circle is

A force given by the relation F=8t , acts on a body of mass 2 kg , initialiy at rest. Find the work done by this force on the body during first 2 seconds of its motion.

A body weighs 63 N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth ?

A body weighs 63 N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth ?

A body is being raised to a height h from the surface of earth. What is the sign of work done by (a) applied force (b) gravitational force ?