Question

Qi When the speed of an object is doubled its Kinetic energy changes:
(a) 2 times
(b) 6 times
(c) 4 times
(d) Remains the same​

Answer 1

Answer:

(c) 4 times

Explanation:

as KE=1/2mv²

then if v is doubled

then KE=1/2m(2v)²

=1/2m4v²

hence it is increased 4 times

Answer 2

Explanation:

Given:

• Speed (v) = 2v

Solution:

We know, K.E = ½mv².

Here, v = 2v

$\implies\:\sf{K.E\:=\:\dfrac{1}{2}\:\times\:m\:\times\:(2v)^2}$

$\:$

$\implies\:\sf{K.E\:=\:\dfrac{1}{2}\:\times\:m\:\times\:4v^2}$

$\:$

Hence, Kinetic energy changes by 4 times (c).