During arm wrestling, participants put arms on the table, and wrestle with the putting the force exerted by both the players is equal where is the action reaction force pair.

A wire is suspended from the ceiling and strecthed under the action of a weight F suspended form its other end. Teh force exerted by the ceiling on it is equal and opposite to the weight.

The two parallel circular loops of wire shown in fig each have a radius R = 20 cm and are separated by a distance a = 0.5 cm. The bottom loop is held fixed and the top loop hangs from one end of the arm of an equal arm balance. Since a is much smaller than R, the magnetic field produced by one loop at the other is practically the same as if both were long straight wires. if the curret in each loop is 20 A, how big is the force of attraction of one loop for the other?

Akhtar, Kiran and Rahul were riding in a motor car that was moving with a high velocity on an express-way when an insect hit the windshield and got struck on wind-screen. Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of motor car (because change in the velocity of insect was much more than that of motor car). Akhtar said that since the motor car was moving with a larger velocity, it exerted a larger force on the insect. As a result, the insect died. Rahul while putting in entirely new explanation said that both the motor car and the insect experienced the same force and same change in their momentum. Comment on these suggestions.

Show that tau = F.d . where tau is torque, F is force applied and d is the bot distance of the particle from the axis of rotation called lever arm.

Ten one-rupee coins are put on top of each other on a table. Each coin has a mass m Give the magnitude and direction of:- the force on the 7th coin (counted from the bottom) due to all the coins on its top,

Ten one-rupee coins are put on top of each other on a table. Each coin has a mass m Give the magnitude and direction of:- the force on the 7th coin by the eighth coin,