The following conversions occur frequently in physics and are very useful. (a) Use 1 mi = 5280 ft and 1 h = 3600 s to convert 60 mph to units of ft/s. (b) The acceleration of a freely falling object is 32 ft/s2. Use 1 ft = 30.48 cm to express this acceleration in units of m/s2. (c) The density of water is 1.0 g/cm3. Convert this density to units of kg/m3.

Solution 10E Given data: 1 mi = 5280 ft 1 = 5280 ft/1 mi. 1 h = 3600 s. (a). A speed of 60 miles per hour is =(60 × 5280)/(3600) ft/s = 88 ft/s. (b).(32 ft/s )(30.48cm/1 ft)(1m/100 cm) = 9.8 m/s . 2 (c).(1.0 g/(g/cm ))(100 cm/1m) (1 kg/1000 g) = 10 kg/m .3 3