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AnkhUNC
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[SOLVED] Constant Acceleration
At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 2.1 m/s^2. At the same instant a truck is 10.2 m down the road and traveling with a constant speed of 8.5 m/s. (a) How far beyond the traffic signal will the automobile overtake the truck? (b) How fast will the automobile be traveling at that instant?
s(t) = 1/2 a * t^2 + v0 * t + s0
a = acceleration
v0 = initial speed
s0 = initial position
Being for the truck
a = 0 m/s^2
v0 = 8.5 m/s
s0 = 10.2 m
and being for the car
a = 2.1 m/s^2
v0 = 0 m/s
s0 = 0 m
the equation will be:
8.5 m/s * t + 10.2 m = (There is a 1/2 here right?) (1/2)2.1 m/s^2 * t^2
Solving this I get 9.156s which is apparently incorrect.
Homework Statement
At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 2.1 m/s^2. At the same instant a truck is 10.2 m down the road and traveling with a constant speed of 8.5 m/s. (a) How far beyond the traffic signal will the automobile overtake the truck? (b) How fast will the automobile be traveling at that instant?
Homework Equations
The Attempt at a Solution
s(t) = 1/2 a * t^2 + v0 * t + s0
a = acceleration
v0 = initial speed
s0 = initial position
Being for the truck
a = 0 m/s^2
v0 = 8.5 m/s
s0 = 10.2 m
and being for the car
a = 2.1 m/s^2
v0 = 0 m/s
s0 = 0 m
the equation will be:
8.5 m/s * t + 10.2 m = (There is a 1/2 here right?) (1/2)2.1 m/s^2 * t^2
Solving this I get 9.156s which is apparently incorrect.