Physics Past Questions and Answers

A \(70 kg\) man ascends a flight of stairs of height \(4 m\) in \(7 s\), The power expended by the man is ____________

A body accelerates uniformly from rest at \(6 ms ^{-2}\) for \(8 sec -\) onds and then decelerates uniformly to rest in the next 5 seconds. The magnitude of the deceleration is ____________

A nail is pulled from a wall with a string tied to the nail. If the string is inclined at an angle of \(30^{\circ}\) to the wall and the tension in the string is \(50 N\), the effective force used in pulling the nail is ____________

If \(M\) and \(R\) are the mass and radius of the earth respectively and \(G\) is the universal gravitational constant, the earth's gravitation potential at an altitude \(H\) above the ground level is ____________

Which of the following statements is not true?