Question

An object of mass m moves horizontally, increasing in speed from 0 to v in a time t. The power necessary to accelerate the object during this time period is:
a: mv^2t/2
b: mv^2/2
c: 2mv^2
d: v sqrt /m2t
e: mv^2/2t

Answer 1

Answer:

Option e is correct.

Explanation:

An object of mass m moves horizontally, increasing in speed from 0 to v in a time t.

We know that,

Work done = change in kinetic energy

$W=\dfrac{1}{2}m(v^2-u^2)$

Here, u = 0

So,

$W=\dfrac{1}{2}mv^2$

Also,

Power = work done/time

So,

$P=\dfrac{\dfrac{1}{2}mv^2}{t}\\\\=\dfrac{mv^2}{2t}$

So, the correct option is (e).