Question

Which of the following vehicles has the most kinetic energy? A. a 300kg motorcycle traveling 60km/h B. a 1,100kg car traveling 60km/h C. a 900kg car traveling 80km/h D. a 2000kg truck traveling 50km/h​

Answer 1

Explanation:

Kinetic energy of an object is given by :

$E=\dfrac{1}{2}mv^2$

Where

m is mass and v is velocity of the object

A. Mass, m = 300 kg.

Speed, v = 60 km/h = 16.67 m/s

$E=\dfrac{1}{2}\times 300\times 16.67^2\\\\=41683.33\ J$

B. Mass, m = 1100 kg.

Speed, v = 60 km/h = 16.67 m/s

$E=\dfrac{1}{2}\times 1100\times 16.67^2\\\\=152838.89\ J$

C. Mass, m = 900 kg.

Speed, v = 80 km/h = 22.22 m/s

$E=\dfrac{1}{2}\times 900\times 22.22^2\\\\=222177.78\ J$

D. Mass, m = 2000 kg.

Speed, v = 50 km/h = 13.88 m/s

$E=\dfrac{1}{2}\times 2000\times 13.88^2\\\\=192654.4\ J$

The kinetic energy in case C is maximum.