(adsbygoogle = window.adsbygoogle || []).push({}); Simple "Motion Along a Straight Line" Problem

Hi new here to PF. I have a simple physics problem but I was confused when the teacher was explaining it (he went a little too fast on this part) so I was hoping you physicians can help me out here.

1. The problem statement, all variables and given/known data

An automobile travels on a straight road for 40km at 30 km/hr. It then continues in the same director for another 40 km at 60 km/hr. (a) What is the average velocity of the car during this 80km trip?(Assume that it moves in the positivexdirection.) (b) What is the average speed?

Given:

Trip was 80km.

First 40 km were traveled at 30km/hr

The second 40km were traveled at 60km/hr

2. Relevant equations

Average velocity = (Delta)x / (Delta) t where x is for position and t is for time.

Average speed = total distance / (Delta) t

3. The attempt at a solution

Okay so I was able to get that for the first 40km it took (4/3) hours by dividing (40km)/(30km/hr). For the next 40km I was able to get that it took (2/3 hours) by dividing (40km)/(60km/hr). In other words, 80km in 2 hrs. So I think that the average speed should be 80km/2hrs = 40km/hr. But I just don't know how to get the average velocity. Should I do the same thing again or something else. I know it is easy but I'm new to physics.

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# Homework Help: Simple Motion Along a Straight Line Problem

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