Part A: The sun produces 3.9 • 10^33 ergs of radiant energy per second. How many ergs of radiant energy does the sun produce in 2.45 • 10^5 seconds?

Part B: Which is the more reasonable measurement of the distance between the tracks on a DVD:

7.4 • 10^–4 mm or 7.4 • 10^4 mm? Justify your answer.

Question

Part A: The sun produces 3.9 • 10^33 ergs of radiant energy per second. How many ergs of radiant energy does the sun produce in 2.45 • 10^5 seconds?

Part B: Which is the more reasonable measurement of the distance between the tracks on a DVD:

7.4 • 10^–4 mm or 7.4 • 10^4 mm? Justify your answer.

welshfella · Answer

Part A 
Just multiply the 2 numbers

spring98 · Answer

the answer would be 9.555

welshfella · Answer

Part B  7.4 * 10^4 mm  = 74 meters

spring98 · Answer

wait so is that how i really do it?^

welshfella · Answer

The first part is 9.555 but what about the exponent of 10 ??

welshfella · Answer

you also have to multiply 10^33 and 10^5

spring98 · Answer

ohhok hold on

spring98 · Answer

so is it 10^165?

welshfella · Answer

No you ADD the exponents

spring98 · Answer

oops  ok so it is 10^40

welshfella · Answer

9.55 * 10^38

welshfella · Answer

* sorry 
9.555 * 10^38

spring98 · Answer

seconds right?

welshfella · Answer

No ergs    amount of radiant energy

spring98 · Answer

thank you very much. You are the best helper ever!! :)

welshfella · Answer

yw
as for part B 
the distances will be very small right?

and numbers like 10^4 are very large!!!