A body moves a distance of 10 m along a straight line under the action of a force of 5 Newton.If the work done is 25 joules. the angle which the force takes with the direction of motion of the body is:
A liquid flows through a pipe of non-uniform cross-section. If A1 and A2 are the cross-section of the portions of the pipe at two points the ratio of velocities of liquid at these points will be