Physics Questions and Answers

The energy contained in a wire when it extended by 0.02m by a force 500 N is

Which of the following statements are TRUE about frictional force?

i. it is always a disadvantage
ii. it is sometimes a disadvantage
iii. it always exist where there is a relative motion of two bodies that are in contact
iv. it is sometimes very useful

A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed

A uniform rod PQ of length 1m and mass 2kg is pivoted at the end p. If load of 14N is placed at the center of the rod, find the force that should be applied vertically upwards at Q to maintain the rod at equilibrium horizontally [g = 10ms^-2]

A body is projected from the earth's surface with the intention of letting it escape from the earth's gravitational field. What is the minimum escape velocity of the body? [Earth's radius = 6.4 x 10³km, g = 10ms^-2]