Q.4.Write two applications of Second law of motion.
Answers
Answer:
Defining Newton’s Second Law of Motion Newton’s second law states that the acceleration of an object depends upon two variables – the net force acting on the object and the mass of the object. The acceleration of the body is directly proportional to the net force acting on the body and inversely proportional to the mass of the body.
According to Newton second law of motion,the Rate of change of a body/object is directed proportional to force applied to it and takes place in the direction in which the force acts.
Force=Mass×Acceleration
The acceleration produced by the body/object is directly proportional to the Force and it is inversely proportional to the mass of the body/object. Since, the acceleration produced is inversely proportional to the mass of a body so if the mass of a body is doubled, it's acceleration will be halved and if the mass is halved then acceleration will get doubled. Also the acceleration produced is inversely proportional to the mass of the body, it means that it will be easier to move light bodies then heavy bodies.
Examples:
You may have noticed that while catching the faster moving cricket ball,a fielder often pulls his hand backward with the moving ball. This is because In doing so,the fielder increases the time during which the high velocity if the moving ball decreases to zero. Therefore, the Acceleration of the ball is decreases and therefore impact of catching the faster moving ball is also reduced and fielder did not get hurt in his hand.
You may have also seen In the case of high jump, a athlete is provided either a cushion or a help of same on the ground to call. A help of same reduced the large Momentum of a falling 'high jumping athlete'. And due to this the rate of changed of momentum of athlete is less due to which a smaller stopping for exacts on the athlete and they does not get hurt.