One person says that the potentil energy of a particular book kept in an almirah is 20 J and the other says it is 30J. Is one of them necessarily wrong?

A book is lifted from the floor and is kept in an almirah. One personn says that the potential energy of the book in increased by 20 J and the other says it is increased by 30 J. Is one of them necessarily wrong?

Consider the two cases: a. A says that the potential energy of a book placed on a shelf is 10J . b. B says that the potential energy of the same book is -10J . Which one of them is wrong? Justify.

Consider the two cases: a. A says that the potential energy of a book placed on a shelf is 10J . b. B says that the potential energy of the same book is -10J . Which one of them is wrong? Justify.

The kinetic energy of a particle executing shm is 32 J when it passes through the mean position. If the mass of the particle is.4 kg and the amplitude is one metre, find its time period.

The product of two rational numbers is (2)/(3) . If one of them is -20 . Find the other number.

Force constants K_(1) and K_(2) of two springs are in the ratio 5:4 . They are stretched by same length. If potential energy stored in one spring is 25 J then potential energy stored in second spring is

A bag contains tickets numbered from 1 to 20. Two tickets are drawn. find the probability that i. both the tickets have prime numbers on them ii. on one there is a prime number and on the other there is a multiple of 4.

Is it true to say that, if in two triangles, an angle of one triangle is equal to an angle of another triangle and two sides of one triangle are proportional to the two sides of the other triangle, then the triangles are similar? Give reason for your answer.

One of the two rectangular components of a force is 20 N and it makes an angle of 30^(@) with the force. The magnitude of the other component is

Two identical spherical masses are kept at some distance. Potential energy when a mass m is taken from the surface of one sphere to the other