Question

A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 4.2 m/s. The car is a distance d away. The bear is 30 m behind the tourist and running at 6.0 m/s. The tourist reaches the car safely.

What is the maximum possible value for d?

Answer 1

v = d/t
t = d/v
v ( Bear ) = 6.0 m/s, v ( Tourist ) = 4.2 m/s
(30 m + d) / 6 m/s = d / 4.2 m/s
4.2 ( 30 + d ) = 6 d
126 + 4.2 d = 6 d
6 d - 4.2 d = 126
1.8 d = 126
d = 126 : 1.8 = 70 m
Answer:
The maximum possible value for d is 70 m.