A car starts from rest and accelerates uniformly over a time of 5.21 seconds for a distance of 110 m. Determine the acceleration of the car.
This is what I did:
accleration=(Vf-Vi)/(t)
Vi=0
Vf=110m/5.21s
t=5.21s
110/5.21/5.21=4.05m/s^2
The actual answer is 8.1m/s^2
How did they get that or what did I do wrong?
This is what I did:
accleration=(Vf-Vi)/(t)
Vi=0
Vf=110m/5.21s
t=5.21s
110/5.21/5.21=4.05m/s^2
The actual answer is 8.1m/s^2
How did they get that or what did I do wrong?
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D = 0.5At^2
110 m = 0.5* 5.21^2*A
110 = .5 * 27.12 *A
13.61A = 110
A = 8.08
Your mistake was to calculate the velocity needed to go 110 m in 5.21 seconds. You did not go that fast for the entire distance. Remember you started from rest, so you must be going faster than that at the end to compensate for going slower than that at the start.
110 m = 0.5* 5.21^2*A
110 = .5 * 27.12 *A
13.61A = 110
A = 8.08
Your mistake was to calculate the velocity needed to go 110 m in 5.21 seconds. You did not go that fast for the entire distance. Remember you started from rest, so you must be going faster than that at the end to compensate for going slower than that at the start.
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110 metres is the distance, NOT the velocity.
I don't know how they got 8.1, actually!
Acceleration = (2d/t^2) = 8.458m/sec^2. Did you miscopy something?
Velocity final = (at) = 8.458 x 5.1 = 43.14m/sec.
I don't know how they got 8.1, actually!
Acceleration = (2d/t^2) = 8.458m/sec^2. Did you miscopy something?
Velocity final = (at) = 8.458 x 5.1 = 43.14m/sec.