Question

What is the kinetic energy of a car of mass 900 kg moving with a velocity of 60 m/s?​

Answer 1

Answer:

Approximately 320 000 Joules

Explanation:

KE = 80 000 J

The KE is directly related to the square of the speed. If the speed is reduced by a factor of 2 (as in from 60 mi/hr to 30 mi/hr) then the KE will be reduced by a factor of 4. Thus, the new KE is (320 000 J)/4 or 80 000 J.

Answer 2

Explanation:

$\huge\underline\mathcal\red{Answer}$

$kinetic \: energy \: (ke) = \frac{1}{2} m {v}^{2}$

$= \frac{1}{2} \times \frac{900}{1000} \times ( {60})^{2}$

$\frac{1}{2} \times 0.9 \times 3600$

$0.9 \times 1800$

$\frac{9}{10} \times 1800$

$= 9 \times 180 = 1620 \frac{m}{s}$