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Please help me with this Physics 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

Please help me with this Physics question! A man stands by a train track to watch-example-1

2 Answers

1 vote

Answer:

D) 11 m/s

Step-by-step explanation:

User YABADABADOU
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7 votes

Answer:

D) 11 m/s

Step-by-step explanation:

We have to calculate the velocity of the hot dog with respect to the observer still outside the train. This velocity will be 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)

By replacing 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.

User Rafael Mueller
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8.2k points