Answer :

To find the power used by a machine that does 36 joules (J) of work in 9 seconds (s), we need to use the formula for power. Power is defined as the rate at which work is done over time, and it is given by the formula:

[tex]\[ \text{Power} = \frac{\text{Work Done}}{\text{Time Taken}} \][/tex]

Let's break down the problem step-by-step:

1. Identify the given values:
- Work Done [tex]\( W = 36 \, \text{J} \)[/tex]
- Time Taken [tex]\( t = 9 \, \text{s} \)[/tex]

2. Substitute these values into the power formula:
[tex]\[ \text{Power} = \frac{36 \, \text{J}}{9 \, \text{s}} \][/tex]

3. Calculate the result:
[tex]\[ \text{Power} = 4 \, \text{W} \][/tex]

So, the power used by the machine is 4 watts (W).

Answer:
C) 4W