**PROBLEM 6. ** The deep space probe Pioneer 10 took 21 months to get from Mars to Jupiter, a distance of 998 million kilometers. Use the factor unit technique to find its average speed in kilometers per hour during that period.

**Solution:**

average speed = distance/time

= (998 x10^6 km/21 months) X (12 months/365 days) X (1 day/24 hours)

= 6.5 x 10^4 km/h, or about 65 000 km/h