Additional Practice on Speed 1. A group of campers and one group leader left a campsite in a canoe.

They traveled at an average rate of 10 km/h. Two hours later, the other

group leader left the campsite in a motorboat. He traveled at an average

rate of 22 km/h. How long had each boat traveled when the motorboat

caught up with the canoe?

a.

canoe: 2.2 h; motorboat: 1 h

b. canoe: 2.2 h; motorboat: 10 h

c. O canoe: 3 2 h; motorboat: 12 h

3

3

d. O canoe: 4.4 h; motorboat: 2 h

Newton's law of cooling states that the rate of change in the temperature t(t) of a body is proportional to the difference between the temperature of the medium m(t) and the temperature of the body. that is, startfraction dt over dt endfraction equals upper k left bracket upper m left parenthesis t right parenthesis minus upper t left parenthesis t right parenthesis right bracket , where k is a constant. let kequals0.04 left parenthesis min right parenthesis superscript negative 1 and the temperature of the medium be constant, m(t) font size decreased by 3 equivalent font size decreased by 3 294 kelvins. if the body is initially at 369 kelvins, use euler's method with hequals0.1 min to approximate the temperature of the body after (a) 30 minutes and (b) 60 minutes.