8. How long does it take a 19 kW steam engine to do 6.8 x 107 J of work?

3.58 * 10³ seconds or 59.65 minutes

Explanation:

We are given;

Power of a steam engine as 19 kW Work done as 6.8 * 10^7 Joules

We are required to calculate time;

We need to know that;

Power = Work done : time Power is the rate of doing work.

19 kW = 19,000 Watt

Rearranging the formula;

time = Work done : power

= 6.8 * 10^7 Joules : 19,000 watt

= 3578.95 seconds

= 3.58 * 10³ seconds

But, 60 seconds = 1 minute

Therefore, t = 59.65 minutes