Question

List some examples of Newton's second law of motion.

Answer 1

Newton's Second Law

Newton's second law of motion states that the net force acting on a body is directly proportional to the rate of change of momentum on the body.

If $F$ is the force applied to a body, $t$ is the instantaneous time and $p$ is the momentum of the body, then Newton's second law of motion can be mathematically expressed as

$F\propto \frac{dp}{dt}$.

Let $m$ be the mass of the body then and $v$ be its velocity, then momentum is written as $p=mv$.

Therefore, $F\propto \frac{d}{dt}\left(mv\right)=m\frac{dv}{dt}=ma$

Hence, Newton's second law of motion gives us the expression that relates the force applied to the mass and acceleration of the body.

Examples

1. If a body is pushed more, it will start moving with higher acceleration, while if it is pushed with less force, it will move will a lower acceleration.
2. An empty box requires less force than a filled box because the mass of the empty box is less than the filled box.
3. A lighter ball will go higher than a heavier one when thrown upwards with the same force, as the lighter ball will require less force to overcome the earth's gravitational force.
4. The force acting on a heavier body during free fall will be more compared to the force acting on the lighter body since the acceleration due to gravity is constant for both the bodies.
5. In order to stop a moving car, force is applied to the wheels that cause deceleration, and eventually, the car stops.