Two simple questions

1. Nov 12, 2006

demode

First Question

'A worker is rolling a 480-N barrel up a 16-m ramp onto a platform 2.0 m above the floor. The efficiency = arrangement is 40%. What is the work output, work input, and effort applied to the barrel..

To find work output, you would just multiply the resistance force (480) by the distance of resistance (2.0) and get 960 right?

To find work input , you would use the given information: Efficiency = Wout / Winput, so 40% = 960 / x = 24 J right?

TO find effort applied, you would just setup Winput = E * De, 24 = X * 16 = 1.5 N right?

Second Question

"16,000 N car is moving up a hill at 12 m/s, hill = 360 m long and 15 m high.. What work does the car's engine do in getting to the top, how long does it take, and what power does the engine do?"

I believe the first part is asking for Woutput, so Woutput = 16,000 * 15 = 240,000 J right?

To find out how long it takes, do we just divide the distance the car has to travel by the velocity? (360 / 12), or am i completely wrong there?