need help physics geniuses?

Question

given;
a car with
m=1500 kg
p= 75watts
v= 120 km per hour

find
a.time it would take the car to reach 1km
b.force exerted in the car during this time
c.the work done by the engine during this time

Answer 1

There are two ways I can read your problem. The first is that the car engine is accelerating your car with a power of 75 watts from an INITIAL velocity of 120 km/hr. The other is that the 75 watts is maintaining a CONSTANT velocity of 120km/hr against the forces of friction and air resistance. Would you care to elaborate?
If it were the latter, the Time it takes to reach 1km is found simply by:
t = d/v = 1km/120 km/hr = 1/120 hrs = 0.5 minutes
The force exerted on the car would be found by the equation:
power = force(velocity) =>
power/velocity = force = 75 watts/ 33 m/s = 2.27 Newtons
The work done would be found by:
work = force(distance)
=2.27N (1000 m) ~ 2270 Joules or by
work = power(time) = 75 watts * 30 seconds ~ 2250 Joules