In which of the following device is the expansion of solid not required?
I. Simple pendulum
II. Fire alarms
III. Thermostat
IV. Bimetallic thermometer
Calculate the gravitation force of attraction between two planets of \(10^{24}\)kg and \(10^{27}\)kg separated by a distance of \(10^{20}\)meters
Mr. F. Abioye observed his image through a plane mirror, kept at a distance 4.7m away from him in his room. At what distance is the image found from Abioye's eye?
