Question

The engine that moves the cables for the San Francisco cable cars delivers 390.3 kW of power for each line. How long does it take for 6.5 ×10^6 J of work (about the amount of work needed to raise a partially loaded cable car up Nob Hill) to be done by this engine?

Answer 1

It would take 16.7 s for the work to be done by the engine.

Step-by-step explanation:

From the question, given: Power = 390.3 kW

Work to be done = 6.5 x
`10^(6)` J

But, power and work done with respect to time, has a relationship of:

Power =
`(work done)/(time)`

So that,

time =
`(work done)/(Power)`

Thus,

time =
`(6.5*10^(6) )/(390.3*10^(3) )`

= 16.6539

time = 16.7 s

Time required is 16.7 seconds.

Thus, it would take 16.7 s for the work to be done by the engine.