One of the rectangular components of a force of 40 N is 20$$\sqrt3$$ N. What is the other rectangular component?

An object dropped in a stationary lift takes time $$t_1$$ to reach the floor. It takes time $$t_2$$ when lift is moving up with constant acceleration. Then,

When a body is placed on a rough plane (coefficient of friction $$=~\propto$$ ) inclined at an angle $$\theta$$ to the horizontal, its acceleration is (acceleration due to gragvity $$=g$$ )

A metal ball of mass 2 kg moving with a velocity of 36 km/h has a head on collision with a stationary ball of mass 3 kg. After the collision, if both balls move together, then the loss in kinetic energy due to collision is