1- Derived units: convert the following watch significant figures.

a) 8.68cm² into in²

b) 27.47 in³ into m³

2- Spacecraft , like the shuttle, travel at speeds of 26,900 miles per hour. Calculate this speed in units of meters per second. ( 1 mile=1.6093km)

3- Convert the following, watch significant figures.

a) 21010³ m into km

b) 118 L into mL

c) 924.47mg into g