Ans. Initially, the carpet and loose dust particles in it are at rest. But when the carpet is hit with a stick, it is suddenly be into motion, but the dust particles in it try to remain in the state of rest because of inertia of rest. And dust comes out of the carpet.
Q. Why is it advisable to tie luggage kept on the roof of a bus with rope ?
Ans. When the luggage is not tied with a rope to the bus, then due to inertia of rest, it will move back when the bus starts moving and will move forward due to inertia of motion when the bus stops. Thus it may fall down So it is advisable to tie the luggage kept on the roof of a bus with rope.
First law of motion: Newton’s First law explains the “natural” motion of an object when it is left free. The law says that- Every object continues in its state of rest, or of uniform motion in a straight line with unchanging speed, unless compelled to do otherwise by forces acting upon it.So, naturally an object at rest will remain at rest and an object moving with a constant speed in a straight line will keep moving, unless they are disturbed by a force.This property of matter to continue its state of rest or of uniform motion is called “Inertia”. Hence, this law is also called the Law of Inertia.
Second law of motion: Newton’s 2nd law of motion relates the external force (F) acting on a body with the mass (m) of the body; and is mathematically written as F = ma, ‘a’ is the acceleration of the body due to the force. It states that the acceleration of a body due to net external force acting on it is equal to the net force divided by the mass of the body.The difficulty you face while pushing or pulling a heavier box compared to a lighter box is explained by the 2nd law of motion.
Third law of motion: This law deals with the forces between bodies that appear in pairs. It says that every action has an equal and opposite reaction. When you stand on the ground, your weight pushes the ground downwards; does this make the ground to move downward? No, because the ground pushes you upward with a force equal to your weight and hence these equal and opposite forces cancel out and you stand on the ground balanced. Force by you on the ground and force on you by the ground are two equal and opposite forces acting in pairs at the surface that is common to both you and the ground.
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