(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

1.How long, in seconds, does it take an automobile traveling 50.0 km/h to become even with a car that is traveling in another lane at 40.0 km/h if the cars' front bumpers are initially 124 m apart?

2.A shopper in a department store can walk up a stationary (stalled) escalator in 30.0 s. If the normally functioning escalator can carry the standing shopper to the next floor in 20.0 s, how long would it take the shopper to walk up the moving escalator? Assume the same walking effort for the shopper whether the escalator is stalled or moving.

2. Relevant equations

1. I assume, nothing besides conversion equations.

2. Nothing really

3. The attempt at a solution

1. I immediately changed 124 m to .124 km. Then I tried to find out how long it would take the 50 km/h car to move .124 km farther. Then I realized that the distance between them still wouldn't be equal as the slower car would have still moved. How does this work? Is there something I'm missing?

2. I tried subtracting the smaller time she took (20 seconds) from the longer time (30) to get 10 seconds but that was way too easy and of course didn't work. Then I tried to find how much longer is 30 seconds than 20 seconds. The answer 1.5, I then divided 20 by 1.5 to see the rate at which she walked but it seemed off so I'm lost.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Relative Velocity Questions

**Physics Forums | Science Articles, Homework Help, Discussion**