Advertisements
Advertisements
प्रश्न
How can Newton's first law of motion be obtained from the second law of motion?
Advertisements
उत्तर
From Newton's second law of motion, F = ma.
If F = 0, then a = 0.
This means that if no force is applied on the body, its acceleration will be zero. If the body is at rest, then it will remain in the state of rest and if it is moving, then it will remain moving in the same direction with the same speed. Thus, a body not acted upon by an external force, does not change its state of rest or motion. This is the statement of Newton's first law of motion.
APPEARS IN
संबंधित प्रश्न
A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block has a magnitude.
Two blocks of equal mass m are tied to each other through a light string. One of the blocks is pulled along the line joining them with a constant force F. Find the tension in the string joining the blocks.
Use Newton's second law of motion to explain the following instance :
A cricketer pulls his hands back while catching a fast moving cricket ball .
Calculate the velocity of a body of mass 0.5 kg, when it has a linear momentum of 5 Ns.
What do you understand by the term momentum?
What do you mean by an impulsive force?
Use Newton's second law to explain the following:
While catching a fast moving ball, we always pull our hands backwards.
A body of mass 2 kg travels according to the law x(t) = pt + qt2 + rt3 where p = 3 ms−1, q = 4 ms−2 and r = 5 ms−3. The force acting on the body at t = 2 seconds is ______.
A woman throws an object of mass 500 g with a speed of 25 ms1.
- What is the impulse imparted to the object?
- If the object hits a wall and rebounds with half the original speed, what is the change in momentum of the object?
What happens when a car brakes to come to a stop?
