Suppose you are on a conveyor belt walkway at an airport. The walkway is moving at 0.50 m/s. You walk backward at 0.80 m/s to hand your suitcase to a friend who is 3.0 m behind you. A security guard stands alongside the walkway watching this. What is your speed relative to the guard?
a. 0.30 m/s
b. 0.50 m/s
c.1.30 m/s
d. 0.80 m/s

Please help me get the correct answer and understand this! :(

Question

Suppose you are on a conveyor belt walkway at an airport. The walkway is moving at 0.50 m/s. You walk backward at 0.80 m/s to hand your suitcase to a friend who is 3.0 m behind you. A security guard stands alongside the walkway watching this. What is your speed relative to the guard?
a. 0.30 m/s
b. 0.50 m/s
c.1.30 m/s
d. 0.80 m/s

Please help me get the correct answer and understand this! :(

noelgreco · Answer

The suitcase, your friend, and his distance from you are not important.

The TSA man is stationary with respect to you and the walkway.  The walkway moves past him at .5 m/s in one direction, you move in the opposite direction (relative to the walkway ) at ,8 m/s.  The TSA man sees .5 - .8 m/s.

anonymous · Answer

0.3m/s in the direction of the friend. It is a simple problem of  velocity addition .
The belt is moving w.r.t. guard with 0.5m/s and you are moving w.r.t. belt with velocity -0.8m/s.[- sign for opposite direction i.e. towards friend].
Addition of velocity gives a velocity of -0.3m/s w.r.t. the guard.