Hey, I was wondering if anyone could help me make sense of this question, it reads
6. Two cyclists, Ann and Bob, travel from P to Q along a straight path. Ann starts from rest as bob passes her at 3.5ms-1. Bob continues at this speed while Ann accelerates at 0.2ms-2 for T seconds until she attains her highest speed. at this moment both cyclists immediately start to slow down with constant but different decelerations, and they both come to rest at Q, 80 seconds after Ann started moving.
a) sketch both the velocity time graphs
b) if both cyclists travel the same distance, find
i) the value of T
ii) the distance between p and Q
iii) the magnitude of bobs deceleration
Thanks for the help, don't worry this isn't for a test or assessment and this is the only question out of 20 that i cant seem to make head nor tail of :P
velocity time graph help (M1) watch
- Thread Starter
- 25-01-2010 22:45
- 26-01-2010 02:14
Erm.....well Bob will start out with a horizontal line at 3.5, and then at T seconds go down with some gradient ending up at 80 seconds.
The other one will start at the origin, go vertical with a gradient of 0.2, and at time T, her velocity will be 0.2T, and at this point will go down again and finish at 80, so will be a lopsided triangle.
As there is only one unknown (T) you should be able to work it out as both areas are the same.
I reckon the area of the first guy is 3.5T + 0.5(80-T)(3.5) and the second guy is 0.5(T)(0.2T) + 0.5(80-T)(0.2T)
you can work that out easy.