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

2. Relevant equations

Equations of motion:

v = u + at

s = 1/2 (u + v) t

s = ut + 1/2at^2

v^2 = u^2 + 2as

3. The attempt at a solution

Hello, onai used the 2nd equation:

30m = 1/2 (3*10^8m/s+3*10^8m/s) t so -> t = 1*10^-7s

but to get the correct solution i need to take t*2 i think. I made a small sketch to this question, but i dont really know why i need to take it times 2, is it because of sending and receiving the signal?

I hope someone can explain this to me.

bwas a lot more confusion for me because of the two time values:

first i useds = v*t

s = 3*10^8m/s * 2.14 * 10^-7s so -> s = 64.2m

this is where i get lost, so now i used the 2nd equation again with the other time value:

64.2m = 1/2 (0m/s + final velocity) * 0.1s so -> v (final velocity) = 1284 m/s

so im pretty sure thats waaay to high, but i think the first part is correct.

Thanks for every answer.

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# Homework Help: Motion involving speed cameras

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