Question

A car moves at a speed of 50 kilometers/hour. Its kinetic energy is 400 joules. If the same car moves at a speed of 100 kilometers/hour, then its kinetic energy will be

Answer 1

1600j

Step-by-step explanation:

ke prop to v^2

ke1/v1^2=ke2/v2^2

400/50x50=joules/100x100

400x2x2

Answer 2

1601.33J

Step-by-step explanation:

Kinetic energy = 1/2 × mv²

Where;

m = mass (kg)

v = velocity (m/s)

To calculate the kinetic energy of the same car at a different speed, we initially need to calculate the mass of the car.

The initial velocity of the car is 50km/hr = 13.89m/s, while the kinetic energy is 400Joules

K.E = 1/2 × mv²

400 = 1/2 × m × 13.89²

400 = 1/2 × m × 192.93

400 = 96.466m

m = 400/96.466

m = 4.15kg

Mass of the car is 4.15kg

K.E = 1/2mv²

If velocity = 100 kilometers/hour = 27.78m/s

K.E = 1/2 × 4.15 × 27.78²

K.E = 1/2 × 3202.67

K.E = 1601.33J