Mass and Inertia

1. Why does a ball rolling on the ground stop on its own if Newton’s first law holds true?

When a ball is rolling on the ground, it will come to a halt due to an uneven external force (friction, gravity, etc.) acting on the ball. “Unless and until an external force acts on a body, it remains at rest or in uniform motion along a straight line,” says the first law of motion. Friction acts as an external force in this scenario, causing the ball to stop on its own.

2. Define Inertia with Examples.

Inertia is a body’s tendency to resist a change in its condition of rest or uniform motion. Inertia is the quality of objects that allows them to remain at rest or, if moving, to continue traveling in a straight line.

Following are the examples:

• When a car is suddenly started, the passengers in it fall backward
• In a moving car, when it suddenly stops, all the passengers fall forward.
• When a car moves along a round curve, the passengers sitting inside are thrown outwards.

3. Why do dust particles fly out when we hit the carpet with a stick?

It’s all due to inertia of rest. When you beat a carpet with a stick, the carpet begins to move, but the dust particles remain in their state of rest. The dust particles fall out of the carpet as a result of the repeated beating, leaving you with a clean carpet.

4. What are factors that influence Inertia?

Inertia depends on mass of an object and force as:

Inertia and mass depends directly on each other. Hence, more the mass of a body more will be its inertia and more will be the force required to change its state which means inertia and force also depends on directly.

Following are the examples:

• A cricket ball has higher inertia than a rubber ball, it takes a great deal of force to change its direction.
• A stone has more inertia than a football that is why it cannot be kicked into air easily.

5. Why is it recommended using a rope to secure any luggage on a bus’s roof?

The motion of a moving vehicle, such as a bus, is not uniform; the vehicle’s speed varies, and it may hit the brakes quickly or make a sharp turn. Due to inertia, the luggage will oppose any change in its state of rest, motion, or direction, and it will tend to fall sideways, forward, or backward. The luggage is secured with a rope to prevent it from falling.

Many events are seen in the field of physics, yet some of them have eluded explanation for a long time. Newton proposed three rules of motion, which became known as Newton’s Laws of Motion. These laws were a novel finding in the physical universe, and they were frequently employed to explain situations that were before unexplainable. Newton’s three laws were utilized to establish a relationship between the motion of objects around us and the natural or external forces operating on them, as we all know. 

A push or pull on an object that causes the body on which it works to accelerate is known as Force. The Newton (N) is the SI unit of force. A force can affect a body in three ways. It has the ability to change the speed of a body, the direction of motion of a body, and the shape of a body. Force is a vector quantity since it has both magnitude and direction. Also, force exists only as a result of a collision. 

The force is no longer felt by the objects if there is no interaction. Similarly, inertia was utilized in conjunction with the first law of motion to describe physical phenomena. Before we look at what inertia is, it’s a good idea to review Newton’s first law: