Question

Calculate the change in kinetic energy of a toy car of mass 4 kg when its speed is raised from 6 meter per second to 18 metre per second

Answer 1

ANSWER:

• Kinetic energy of the toy car = 576J

GIVEN:

• Mass = 4 kg

• Initial velocity = 6 m/s

• Final velocity = 18 m/s

TO FIND:

• Change in Kinetic energy of the toy car.

EXPLANATION:

$\large{\bold{ \Delta K.E = \dfrac{1}{2}m(v^2 - u^2)}}$

m = 4 kg

v = 18 m/s

u = 6 m/s

K.E = 1/2 × 4 (18² - 6²)

Split (18² - 6²) into ( 18 - 6)(18 + 6)

K.E = 1/2 × 4( 18 - 6)(18 + 6)

K.E = 2(12) (24)

K.E = 24 × 24

K.E = 576 Joules

Hence the change in kinetic energy of a toy car is equal to 576 Joules.