Work And Energy...

A body moves a distance of 10m along a straight line under the action of a force of 5N. If the work done is 25 J , the angle which the force makes with the direction of motion of the body is-

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

The potential energy of a particle is determined by the expression U = α (x²+ y²), where α is a positive constant. The particle begins to move from a point with the coordinates (3, 3) (m), only under the action of potential field force. Then its kinetic energy T at the instant when the particle is at a point with the coordinates (1, 1) (m) is