Identify the wrong statement among the following. Rewrite them by making necessary corrections.
a) Work and energy have different units.
b) When an aeroplane takes off, the work done by its weight is positive.
c) The potential energy of spring increases when it is extended and decreases when it is compressed.
d) If the work done by external forces on a system is negative then the energy of the system decreases.
e) When a body is falling freely from a height, its kinetic energy remains constant.
f) The unit of power is watt.

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Solution

Wrong statements -
(a) They have same unit - Joule(J).
(b) It is negative because force (of weight) and displacement is in opposite direction.
(e) kinetic energy increases as velocity increases.

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