Question

A truck travels at a speed of 80.0 km/h and has a mass of 2 000 kg. What is its kinetic energy?

Answer 1

By the definition of the kinetic energy, we get:

$$KE = \dfrac{1}{2}mv^2,$$ $$KE = \dfrac{2000 \ kg}{2} \cdot (80 \ \dfrac{km}{h} \cdot \dfrac{1000 \ m}{1 \ km} \cdot \dfrac{1 \ h}{3600 \ s})^2 = 493827 \ J.$$

Answer:

$KE = 493827 \ J.$