Final answer:
To determine how long a 60W light bulb would be on if it did 2400 J of work, divide the energy by the power, resulting in the bulb being on for 40 seconds.
Step-by-step explanation:
The question asks about the time a 60W light bulb would take to use 2400 joules of energy. To find this, we use the formula that relates power (P), energy (E), and time (t):
E = P × t.
To find the time (t), rearrange the formula:
t = E / P.
So, with the given values:
t = 2400 J / 60 W,
t = 2400 / 60,
t = 40 seconds.
This calculation shows that the correct answer is A. 40 seconds.