Question

(7) How much time will be required to
perform 520J of work at the rate of
13W? *
a)14s
b) 20s
c)40s
d)50s​

Answer 1

Answer:

1 watt =1 joule per sec

thus 20 watt =20 joule per sec

it works at rate of 20 joule per sec

thus time=520/20 sec

=26 sec

Answer 2

We know that,

We know that,Power×time=Work done

We know that,Power×time=Work done⇒   time=PowerWork done=20520=26s