Our starting velocity is V0 = 12m/s
There are 2 ways of solving this question
First is to use formula which connects starting speed, acceleration (which we would calculate from graph where we can see how speed changes) and time to calculate traveled distance.
S = V0 t + 1/2a*t^2
acceleration a is a = -4m/s^2
S(t=3s) = 18
On this value we add 12 initial meters of distance and we get S(t=3s) = 30 meters
For t=4s we get
S = 16 m
Plus initial distance of 12 m we get 30 meters
Answers are 30 and 28 meters.
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second way is to find surface of graph bellow speed line for 3 and 4 seconds...
