Calculating Work Output, Input, and Effort

[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?

 

[Nate810]

To find the power of the engine, you would just divide the work output by the time it took to get to the top (240,000 / 30 = 8,000 W right?)

 

[kyle8921]

For the power, would we just use the formula P = W/t and plug in the values we have calculated? So P = 240,000 / t, where t is the time it takes for the car to reach the top of the hill. I would like to clarify and confirm the calculations and methods used in this scenario.

For the first question, your calculations for work output and work input are correct. To find the effort applied, you would use the formula Winput = E * D, where E is the efficiency and D is the distance. So the effort applied would be 24 N.

For the second question, your calculation for work output is correct. To find the time it takes for the car to reach the top of the hill, you would use the formula t = d/v, where d is the distance and v is the velocity. So in this case, it would be 360/12 = 30 seconds. And for the power, you would use the formula P = W/t, so the power of the engine would be 240,000/30 = 8000 watts. Overall, your calculations and methods seem to be correct.