Answer:
40 seconds
Step-by-step explanation:
Power is defined as the rate of work done per unit time, expressed as
where P represent power in Watts, W is work done in Joules and t is time taken. Making t the subject of the above formula then
and substituting Work done, W with 1600 J while Power, P with 40 W then
Therefore, the time taken is equivalent to 40 s