## Physics: Principles with Applications (7th Edition)

$$1 \times 10^{5} \frac{km}{h}$$
Average speed is the distance divided by the time. $$1 \times 10^{9} \frac{km}{yr} \frac{1 year}{365.25 days} \frac{1 day}{24 h}= 1 \times 10^{5} \frac{km}{h}$$