Answer to Question #259302 in Classical Mechanics for Hridita Chowdhury

Question

1.As a smart physics student,mention a law of physics which is very important to you?Explain with an example why do u think that the law is very important.

2.Say,Mr X runs on a plain land and jump from a spot in forward direction.Recognize and describe his jumping motion through an equation and make an argument for your answer.

Answer 1

1. My favorite law of physics in my opinion is Newton's second law (although I am sure all laws are equally important). Newton's second law allows us to move and explain many things we see every day. For example, a car is stuck on an icy snowy inclined road and with throttle down it stays at one place although the wheels are spinning. It means that the force of gravity equal the force of traction of wheel, therefore, to make the car move, we need to apply a little force (push the car) to disbalance the equilibrium and help the driver.

2. His jumping motion consists of horizontal motion at constant speed (ignoring air resistance) and vertical motion under the influence of gravity. The range depends on the his horizontal speed:

$$x(t)=vt,t<\sqrt{2h/g},$$

where h is height of the spot.