Consider a hypothetical planet whose mass and radius are both half that of Earth. If g is the acceleration due to gravity on the surface of Earth, the acceleration due to gravity on the planet will be
Two trains are moving in the same direction at the speed of 24 km/hr and 50 km/hr. The time taken by faster train to cross a man sitting in the slower train is 72 seconds. What will be the length (in metres) of the faster train?