PDA

View Full Version : Exponents - check answer please



lrivetz
06-02-2006, 05:31 AM
(1/3) neg 4 = 1/81

(1/2) neg 2 = 1/4

If the speed of light is 3.00 x 10 ^ 8 m/sec, how long does it take light to travel 2.29 x 10 ^ 11 m, the distance from the sun to the Mars? = 6.87 x 10 ^ 19 m/sec

Thank you.

tkhunny
06-02-2006, 07:18 AM
If the speed of light is 3.00 x 10 ^ 8 m/sec, how long does it take light to travel 2.29 x 10 ^ 11 m, the distance from the sun to the Mars? = 6.87 x 10 ^ 19 m/secThere's a hint in the problem statement. "How long...?" You should end with a TIME.

(2.29 * 10^11 m)/(3.00 x 10 ^ 8 m/sec) = ?? seconds

lrivetz
06-02-2006, 07:51 AM
If the speed of light is 3.00 x 10 ^ 8 m/sec, how long does it take light to travel 2.29 x 10 ^ 11 m, the distance from the sun to the Mars? = 6.87 x 10 ^ 19 m/secThere's a hint in the problem statement. "How long...?" You should end with a TIME.

(2.29 * 10^11 m)/(3.00 x 10 ^ 8 m/sec) = ?? seconds

7.63 x 10 ^ 2

The answer has to be in scientific notation.

tkhunny
06-02-2006, 08:23 AM
Good start.

I think you have the arithmetic, but you seem to have lost your units.

lrivetz
06-02-2006, 08:41 AM
Good start.

I think you have the arithmetic, but you seem to have lost your units.

7.63 x 10 ^ 2 m/sec

how about these:


(1/3) neg 4 = 1/81

(1/2) neg 2 = 1/4

Denis
06-02-2006, 10:59 AM
(1/3) neg 4 = 1/81

(1/2) neg 2 = 1/4


Post those like THIS: (1/3)^(-4) ; (that's 1/3 to the power minus 4)

You're close: answers should be 81 and 4; I'll let you figure out why 8-)

tkhunny
06-02-2006, 11:47 AM
7.63 x 10 ^ 2 m/secStill no.

Think for a moment, BEFORE you do any arithemetic, "What SHOULD the units be in the final result?"