As you throw a heavy ball upward, is there any change in the normal force on your feet?

A person (40 kg) is managing to be at rest between two verticle walls by pressing one wall A by hi hands and feet and the other wall B by his back figure. Assume that the friction coefficient between his body and the walls is 0.8 and that limiting friction acts at all the contacts. a. show that the person pushes the two walls with equal force. b. find the normal force exerted by either wall on the person Take g=10 m/s^2 .

A person sitting in a train moving at constant velocity throws a ball vertically upwards. How will the ball appear to move to an observer? (i) Sitting inside the train (ii) Standing outside the train

A block is placed on the horizontal surface. There are two forces acting on the block. One, the downward pull of gravity and other a normal force acting on it. Are these forces equal and opposite? Do they form action - reaction pair? Discuss with your friends.

Three identical cars A,B and C are moving at the same speed on three bridges. The car A goes on a plane bridge, B on a bridge convex upward and C goes on a bridge concave upward. Let F_A,F_B and F_C be the normal forces exerted by the cars on the bridges when they are at the middle of bridges

Consider the situation of the previous problem. Take the table and the ball as a system friction is then an internal force. As the ball slows down the momentum of the system decreases. Which external force is responsible for this change in the momentum?

You accelerate your car forward. What is the direction of the frictional force on a package resting on the floor of the car?

Can you say that salt is a liquid on the basis of change in its shape? Justify your answer. Take a sponge. Observe its shape.

Jogging every day is good for health. Assume that when you jog a work of 500 kJ is done and 230 kJ of heat is given off. What is the change in internal energy of your body?