Question

Which of the following best represents the earth's orbital speed around the sun?

A) 3 × 10-4 meters per second
B) 3 × 104 meters per day
C) 3 × 104 meters per second
D) 3 × 10-4 meters per day

Answer 1

C) 3 x 10^4 meters per second.

Explanation:

The earth's orbital speed around the sun is 30 kilometers per second. Since, the given options list the speed in meters per day or meters per second we have to convert speed into these units.

Since,

1 kilometer = 1000 meters, we can write:

`30 \text{ km/sec}=( 30 km)/(sec) \\\\= \frac{30 * 1000 \text{ meters} }{sec}\\\\= \frac{30000\text{ meters} }{sec}\\\\=\frac{3 * 10^(4) \text{ meters} }{sec}`

= 3 x 10^4 meters per second

which matches with the answer in option C.

We obtained the result 30000 m/s. We expressed it using the power of 10 i.e scientific notation using the following steps:

30000 = 3 x 10000 = 3 x 10 x 10 x 10 x 10 = 3 x 10^{4} m/s

Therefore, the earth's orbital speed around the sun is 3 x 10^4 meters per second.