Work= force x displacement :)
That ratio is called"efficiency". It doesn't need to be a percent.
It can just as well be a fraction or a decimal number.
<span>6160 joules
to lift 1 newton 1 metre requires 1 joule
there are 10 newtons in one kilo
so 77(kg) x 8 (metres) x 10 (newtons/kilo) = 6160 joules</span>
Answer:
A. 

B. rev=10.79rev
Explanation:
A.
500rpm

the time is about 2.60s knowing the acceleration is:

so:


B.
The CD stop so the final velocity is vf=0 so:
Total revolutions:

