Question

The work done required to stop a car of mass 1000kg moving at a velocity of 20 m/s will be ??

Answer 1

Mass of the car (m) = 1000 kg

Velocity of the car (v) = 20 m/s

The work done by the force is defined as the change in the kinetic energy of the body.

Initial kinetic energy = $\frac{1}{2} \times m \times v^2$

Initial kinetic energy = $\frac{1}{2} \times 1000 \times 20^2$

Initial kinetic energy = 200000 Joules

Final kinetic energy = 0 J

Hence, the work done in stopping the car = (200000 - 0 )Joules

Work done = 200000 Joules

Answer 2

Answer:

Mass of the car (m) = 1000 kg

Velocity of the car (v) = 20 m/s

The work done by the force is defined as the change in the kinetic energy of the body.

Initial kinetic energy = \frac{1}{2} \times m \times v^2

2

1

×m×v

2

Initial kinetic energy = \frac{1}{2} \times 1000 \times 20^2

2

1

×1000×20

2

Initial kinetic energy = 200000 Joules

Final kinetic energy = 0 J

Hence, the work done in stopping the car = (200000 - 0 )Joules

Work done = 200000 Joules