Question

(a) Work is said to be done by a force only when _________

(b) Work done = Force $\times$ _________

(c) The energy of a body is its capacity to do ______

(d) The S.I. unit of energy is ______

(e) The potential energy of a body is due to its ______ and kinetic energy of body is due to its ______

(f) Gravitational potential energy U = mass $\times$ force of gravity on unit mass $\times$ _________

(g) Kinetic energy = $\frac{1}{2}\times mass\times$_________

(h) Power P = ______ / time taken.

(i) The S. I. unit of power is ______

(j) 1 H.P. = ______ W

Answer 1

(a) Work is said to be done by a forte only when the body moves.
(b) Work done = Force $\times$ distance moved in direction of the force.
(c) The energy of a body is its capacity to do work.
(d) The S.I. unit of energy is joule.
(e) The potential energy of a body is due to its state of rest or position and kinetic energy of the body is due to its state of motion.
(f) Gravitational potential energy U = mass $\times$ force of gravity on unit mass $\times$ height.
(g) Kinetic energy = $\frac{1}{2}\times mass\times$ $spee{d}^2$
(h) Power P = $\frac{work}{timetaken}$.
(i) The SI unit of power is watt.
(j) 1 H.P. = 746 W