Chapter 5: Exercises with Solutions

Section 5.5Motion5.5 Solutions1. We are trying to solve for d, so d = vt is the formula we want to use.d = vt= 30 mih × 5 h= 150 mi3. We are trying to solve for t, so divide d = vt by v on each side first.t = d v120 mi=30 mi/hr= 120 mi × 1 hr30 mi= 4 hrs5. We are trying to solve for v, so divide d = vt by t on each side first.v = d t250 mi=5 hrs= 50 miles per hour7. We are trying to solve for d, so d = vt is the formula we want to use. But noticethat the rate v is given in ft/s, while time t is given as 5 minutes. We must first makethe units match, so convertNow plug into the formula.t = 5 min= 5min × 60 s1 min= 300 sd = vt= 15 ft s × 300 s= 4500 ftVersion: Fall 2007