A car and a coach travel at different uniform speeds on a straight horizontal road. The speeds of the car and the coah are 12ms^-1 and 10ms^-1.
At the instant, while the car lags behind the coach by 20m, the car accelerates uniformly at 0.5ms^-2 and the coach keeps travelling at a constant speed. How long would it be for the car to overtake the coach?
f.4 phys,,about cars
2008-10-13 1:03 am
回答 (1)
2008-10-13 5:05 am
✔ 最佳答案
The speed of the car relative to the coach is (12-10) m/s = 2 m/sUsing equation of motion,
u = 2 m/s, a = 0.5 m/s2, s = 20 m, t =?
use s = ut + (1/2)a.t^2
20 = 2t + (1/2)(0.5)t^2
solve for t gives t = 5.8 seconds
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