- #1
mcintyre_ie
- 66
- 0
Ok, so I am having troule with yet another accelerated linear motion question... i got a 40% on my last exam, and i need at least a 90% on this one to keep a decent average... any help is desperately needed and very much appreciated :)
So here it goes:
(A) A particle is projected vertically upwards with velocityum/s and is at a height h after t1 and t2 seconds respectively. Prove that:
t1.t2 = (2h)/g
(B) A car accelerates uniformly from rest to a speed v m/s. It then continues at this constant speed for t seconds and then decelerates uniformly to rest.
The average speed for the journey is (3v)/4
(i) Draw a speed-time graph and hence, or other wise, prove that the time for the journey is 2t seconds.
(ii) If the car driver had observed the speed limit of (1/2)v, find the least time the journey would have taken, assuming the same acceleration and deceleration as in (i).
Arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!
So here it goes:
(A) A particle is projected vertically upwards with velocityum/s and is at a height h after t1 and t2 seconds respectively. Prove that:
t1.t2 = (2h)/g
(B) A car accelerates uniformly from rest to a speed v m/s. It then continues at this constant speed for t seconds and then decelerates uniformly to rest.
The average speed for the journey is (3v)/4
(i) Draw a speed-time graph and hence, or other wise, prove that the time for the journey is 2t seconds.
(ii) If the car driver had observed the speed limit of (1/2)v, find the least time the journey would have taken, assuming the same acceleration and deceleration as in (i).
Arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!