Question

How much work do you do when you push a 400 kg car for 6 m with a force of 300 N? What is the car’s final speed if all your work became kinetic energy?

Answer 1

Answer:

Work=1800 J

Speed=3m/s

Explanation:

Work is product of force and distance moved, expressed as

W=Fd

Where F is force and d is distance in meters

Substituting 300 N for force and 6 m for d then

W=300*6=1800 J

Kinetic energy is given by

KE=½mv²

Where m is the mass and v is velocity

Here, KE=W hence

W=½mv²

Making v the subject then

$v=\frac {2W}{m}$

Substituting 1800J for W and 400 kg for m then

$v=\frac {2*1800}{400}=3m/s$

Therefore, velocity is 3 m/s