Question

Xavier starts 5 feet away from a motion detector. He then walks away from the detector at a rate of 0.5 ft/sec for 4 seconds. He remains still for 2 seconds, and then walks toward the detector at a rate of −2 ft/sec for 3 seconds. How far in feet is Xavier from the motion detector when he finishes his walk?

Answer 1

1 foot away from motion detector

Explanation:

Given that:

Initial Position = 5 feets away from detector

Distance moved away = 0.5ft/sec for 4 seconds ; distance moved away = 0.5 * 4 = 2 feets

Total distance away = 5 feets + 2 feets = 7 feets

Distance moved towards motion detector :

-2 ft/sec for 3 seconds ;

Distance = speed * time

Distance moved = (-2ft/sec * 3) = - 6 feets

Hence, distance in feets from motion detector :

7 feets - 6feets = 1 feet away from motion detector