Log in

View Full Version : Kinematics help? How to calculate acceleration velocity with just distances and times


clemross
Sep 7, 2010, 02:48 PM
Question: A, B and C are three points on a straight road such that AB= 80metres and BC=60metres. A car traveling with uniform acceleration passes A, B and C at times T= 0, T=4s and T=6s respectively. Modelling the car as a particle find it acceleration and velocity at point A...

Any help?? Many thanks :)

Unknown008
Sep 7, 2010, 09:58 PM
1. Draw a quick sketch.

2. Since there is a uniform acceleration, the motion of the car can be written as:

s = ut + \frac12 at^2

So, you then have two equations:

80 = u(4) + \frac12 a(4)^2

60 +80= u(4+6) + \frac12 a(4+6)^2

Solve for u and a, the velocity of the car at A and its acceleration.

Post your answer! :)