Dynamics and Equilibrium - Physics Learning 2

What is net force?

Answer: The resultant of all the forces acting on a body is called net force. For example a book lying on table has net force equal to zero.

Why book placed on table stays there?

Answer: It is due to first law of motion, which states that; an object at rest will remain in this state until a force acts on it and vice versa. A book placed on the table will stay there in state of rest until a force acts on it to displace it from it's position.

Why ball rolling on rough surface stops earlier?

Answer: Friction is an opposing force, i-e it a force which opposes the motion of objects. The ball rolling on a rough surface will stop earlier than the ball rolling on smooth surface because a rough surface will offer more frictional force than the smooth one. Thus rough surface offers more opposition than a smooth surface.

Why passengers fall outward on sharp turn?

Answer: When bus takes a sharp turn, passengers inside the bus fall outwards due to property of inertia. As the passengers try to keep their motion in straight line so they fall outwards.

Define Newtons 2nd law of motion

Answer: When a net force acts on a body, it produces acceleration in it in the direction of applied net force. This acceleration is directly proportional to the net force acting on body and inversely proportional to the mass of object. Mathematically a = F⁄m.