Question

A car is moving with a speed of 15kmh-¹ and another identical car is moving with a speed of 30kmh-¹ . find the ratio of their kinetic energy. ​

Answer 1

Answer:

indentical car has more 15 kinetic energy

Answer 2

Answer:

K.E. of car B is 4 times K.E. of car A.

Explanation:

Two identical cars means, they have equal mass

K.E. $= \frac{1}{2}mv^{2}$

Let m be the mass of each car

Kinetic energy of car A = $\frac{1}{2}m$ x $15^{2}$ = $\frac{225}{2}m$

Kinetic energy of car B =  $\frac{1}{2}m$ x $30^{2}$ = 450m

$\frac{K.E.ofA}{K.E.ofB}$  = 225m /2×450m = $\frac{1}{4}$ = 1:4

K.E. of car B is 4 times K.E. of car A.

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