A car stopped after emergency braking. The skid mark left by the cars was 22.3 m long. Assume that friction between the road and tyres was 0.65 times that of the weight of the car. Estamate the speed of the car when it began to skid.
A. 5.38m/s
B. 12.0m/s
C. 16.2m/s
D. 17.0m/s
Ans:D
Thanks
Phy past paper II 2006 Q4
2007-04-21 9:38 am
回答 (1)
2007-04-21 9:45 am
✔ 最佳答案
the road and tyres was 0.65 times that of the "weight" of the car...所以 friction = 0.65 x mg
net force = ma
0.65mg = ma
a = 0.65 x 10
=6.5ms ^ -2
再sub返d數字落v ^2 - u^2 = 2 as 就計到la~~^^
2007-04-21 01:46:39 補充：
0.65 times that of the ((weight)) of the car
參考: 尼題絕對係陰人牙...=0=
收錄日期: 2021-04-23 16:54:07
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