Question

A man stands by a train track to watch the train car go by. Inside, a man walks through the train car eating a hot dog (the hot dog is moving 1 m/s towards his mouth). Determine the hot dog's velocity with respect to the man standing still outside of the train car.
A) -11 m/s
B) -9 m/s
C) 9 m/s
D) 11 m/s

Answer 1

Answer:

D) 11 m/s

Explanation:

The problem asks us to calculate the velocity of the hot dog with respect to the observer stationary outside the train. This velocity is given by:

$v=v_t + v_m + v_h$

where

$v_t=+10 m/s$ is the velocity of the train (towards right)

$v_m=+2 m/s$ is the velocity of the man (towards right)

$v_h=-1 m/s$ is the velocity of the hot-dog (towards left, so we put a negative sign)

Substituting the numbers into the equation, we find

$v=+10 m/s+2 m/s-1 m/s=+11 m/s$

and the positive sign means the velocity is toward right.

Answer 2

Answer:

D) 11 m/s

Explanation: