Energy Units? (Kilowatt Joules etc)?

Question

I need help with a few problems, I dont really know how to approach them

You can use 192,000 Joules of energy to light a light bulb for 20 minutes. What is the wattage of the bulb?

and
If a power plant generates up to 2,000 MW of energy, how many 25 watt light bulbs can the plant power?

Thanks for the help!

Answer 1

1) Watt is a unit of power defined as:
1 W = 1 J/s
or
power = energy / time
192,000 J / 1200 s = 160 J/s = 160 W

2) Mega (M) = 10^6 = one million
So you have 2,000 million watts = 2 billion watts
2,000,000,000 watts / 25 watts/bulb = 80,000,000 bulbs (8 followed by 7 zeros, not 8)

Answer 2

ok. simply put, a watt is a joule/second.

So for the first problem it would be 192000 watts. Or 192 kilowatts

and for the second problem you have 2000 MW/25 watts. if you convert MW's to watts. you get 800000000 light bulbs