A body is initially at rest. It undergoe | Class 11 Physics Chapter Work Energy and Power, Work Energy and Power NCERT Solutions

Question:

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to

(i) t½    (ii) t   (iii) t3/2   (iv) t2

Answer:

(ii) t

Mass of the body = m

Acceleration of the body = a

Using Newton's second law of motion, the force experienced by the body is given by the equation:

F = ma

Both m and a are constants.Hence, force F will also be a constant.

F = ma = Constant … (i)

For velocity v, acceleration is given as,

a  =  dv / dt  =  constant

dv  =  Constant x dt

v =  αt             ....... (ii)

where α is another constant 

v ∝ t       ......... (iii) 

Power is given by the relation:

P = F.v

Using equations (i) and (iii), we have:

P ∝  t

Hence, power is directly proportional to time.


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Welcome to the NCERT Solutions for Class 11 Physics - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 9: A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The pow....