- #1
oliampian
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Homework Statement
A car sits in an entrance ramp to a freeway, waiting for a break in the traffic. The driver sees a small gap between a van and an 18-wheel truck and accelerates with constant acceleration along the ramp and onto the freeway. The car starts from rest, moves in a straight line, and has a speed of 17.0 m/s when it reaches the end of the ramp, which has length 117 m .
1) What is the acceleration of the car?
2) How much time does it take the car to travel the length of the ramp?
3) The traffic on the freeway is moving at a constant speed of 17.0 m/s . What distance does the traffic travel while the car is moving the length of the ramp?
Known:
-Vo = 0 (since the car starts from rest)
-Speed = 17.0 m/s
-Distance = 117m
Homework Equations
speed = distance traveled / time
v(t) = vot + at
x(t) = xo + vot + 1/2at2
The Attempt at a Solution
1) My attempt at finding the acceleration of the car was figuring out the speed is distance traveled divided by time. So in order to find the time it took for the car to reach the end of the ramp I did:
speed = distance traveled / time
17 = 117 / time
17 * time = 117
time = 117 / 17 = 6.8826
Then I plugged the time I found into the equation v(t) = vot + at2:
v(6.8826) = 0(6.8826) + a(6.8826)
17 = a(6.8826)
2.47 = a
2) What I found in question 1:
speed = distance traveled / time
17 = 117 / time
17 * time = 117
time = 117 / 17 = 6.8826
3) I just don't know how to start it. I do think I need to use the position equation.
Both my answers for number 1 and 2 are wrong and I think I'm just not using the right formulas or thinking about this equation correctly. Thanks in advance for any help that I may receive!
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