A loaded ore car has a mass of 880 kg and rolls on rails with negligible friction. It starts from rest and is pulled up a mine shaft by a cable connected to a winch. The shaft is inclined at 28.0° above the horizontal. The car accelerates uniformly to a speed of 2.20 m/s in 11.5 s and then continues at constant speed.

Question

What maximum power must the winch motor provide?

Answer 1

Gravity Force component down track = 880 * 9.8 * sin 28
= 4049 Newtons
acceleration =a = 2.20 / 11.5 = .191 m/s^2
Force = m a = 880 * .191 = 168 Newtons
max Power = force * max velocity = 168*11.5 max = 1933 Watts

Answer 2

I confused the time with the speed in the last line
max Power = force * max velocity = 168*2.2 max = 370 Watts

Answer 3

its not correct...because that is what i did too

Answer 4

A loaded ore car has a mass of 880 kg and rolls on rails with negligible friction. It starts from rest and is pulled up a mine shaft by a cable connected to a winch. The shaft is inclined at 28.0° above the horizontal. The car accelerates uniformly to a speed of 2.20 m/s in 11.5 s and then continues at constant speed

What maximum power must the winch motor provide?

Answer 5

Whoa!
I left out gravity
Total force = mass * acceleration
F - 4049 = m a = 168 N
F = 4049+168 = 4217 N
power = 4217*2.2 = 9277 Watts