Question

If the velocity of a body increases by 3 times the precious value, the percentage change in K.E. is ?

K.E. is Kinetic energy.
It's formula is K.E. =
$\frac{1}{2} \times m \times v ^{2}$



a) 1500%
b) 800%
c) 15%
d) 900%

Please answer my question ASAP, I will mark it THE BRAINLIEST....

Answer 1

Answer = 1500%.

There is a difference in "increased to " and "increased by ". Increased by means additional extra amount. " Increased to " means the final amount.

Here in the question, "increased by ", it is stated.
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KE = $\frac{1}{2} m v^2$
where m = mass, v = velocity of the body.

Initial KE = $KE_1= \frac{1}{2} m \: v_1^2$
Velocity increases by 3 times. It means that it becomes 4 times. Because v2 = v1 + 3 v1 = 4 v1.

Final KE =
$KE_2 = \frac{1}{2} m \: v_2^2 = \frac{1}{2} m \: 16 \: v_1^2\\= 16 \: KE_1\\Increase \: in \: KE = 15 \: KE_1 \\Percentage \: increase = \frac{15 KE }{KE }* 100 = 1500%$

So answer is 1500%.

Answer 2

the answer is 1500 %