Rohit placed a pencil perpendicular to principal axis in front of a converging
mirror of focal length 30 cm. The image formed is twice the size of the pencil.
Calculate the distance of the object from the mirror.

The speed of light can be used to measure the

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?

Sunidhi made a study chart about changes in states of matter. which headings best complete the chart?