A 12kW motor moves a 1000kg car at what constant velocity, if the motor applies a force that equals 2000N? Also, of the motor for 2.75s, what amount of work has the motor done on the car. (Show working out)

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Physics

Cutie

27 May, 22:30

A 12kW motor moves a 1000kg car at what constant velocity, if the motor applies a force that equals 2000N? Also, of the motor for 2.75s, what amount of work has the motor done on the car. (Show working out)

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Answers (1)

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Tamia Jacobs · Answer 1

Given data

Power = 12 KW,

mass (m) = 1000 kg,

Force (F) = 2000 N,

time (t) = 2.75 s

Determine

1. Velocity (v) = ?

2. Work (W) = ?

We know that Power (P) = Rate of doing work

= (Work : time) KW

Also we know that Work = F * displacement

Force = m. a N

=> 2000 = 1000 * a

=> a = 2 m/s²

And we know that acceleration (a) = rate of change of velocity

= v : t

=> v = a * t

= 2 * 2.75

= 5.5 m/s

Now determine the Power P = Work done : time

12 = W : 2.75

W = 12 * 2.75

= 33 KJ

= 33000 J