1. The water current of a river is having breadth . To cross the river the first boatman started moving to make an angle with the water current with velocity and the second boatman started moving perpendicularly of the river with velocity.
2. The volume of an air bubble becomes double when it comes from the bottom of a lake to the surface of water. Atmospheric pressure .
4. The diameter of water filled well is , a pump can raise of water at height and throws with a velocity of . Another pump of power SHP makes the water filled well empty.
5. The length of string and diameter of bob of a simple pendulum on the earth surface are and respectively. The pendulum has taken to the planet mars. The mass of the planet mars is 0.11 times of the earth mass and radius is 0.532 times of the earth radius.