A body of mass 2 kg is thrown up vertically with K.E of 490 joules If the acceleration due to gravity is 9.8 m/s2 the height at which the K.E of the body becomes half its original value is give by:
The unit of electric current 'ampere' is the amount of current flowing through each of two parallel wires 1 m apart and of infinite length will give rise to a force between them equal to
A train of 150 m length is going towards north direction at a speed of 10 ms-1. A parrot flies at a speed of 5 ms-1towards south direction parallel to the railway track. The time taken by the parrot to cross the train is equal to
The initial velocity of a body moving along a straight line in 7 m/s. It has a uniform acceleration of 4 m/s2. The distance covered by the body in the 5th second of its motion is
A photocell with a constant p.d. of V volt across it illuminated by a point source from a distance of 25 cm. When the source is moved to a distance of 1m, the electrons emitted by the photocell
