Given
d = |300 -48t|
Find
t when d=60
Solution
Put in the value for d and solve.
60 = |300 -48t|
This resolves to two equations:
First
-60 = 300 -48t . . . . the absolute value changes the sign of its content
0 = 360 -48t . . . . . add 60
0 = 7.5 -t . . . . . . . . divide by 48
t = 7.5
Second
60 = 300 -48t . . . . . the absolute value leaves the sign of its content unchanged
0 = 240 - 48t . . . . . . subtract 60
0 = 5 - t . . . . . . . . . . divide by 48
t = 5
Summary
The car is 60 feet from you at times t=5 seconds and t=7.5 seconds.
