A car moving at speed 50 applied a braking force F
and the car stops in 20m. Find F.
Given mass of car is 1500kg.
physics about force
2008-02-18 2:50 am
回答 (3)
2008-02-18 2:59 am
✔ 最佳答案
v^2-u^2 = 2as0-50^2=2(a)(20)
a=-62.5ms-2
F=ma
F=1500 x -62.5
F=-93750N(-ve value means the force is towards the backwards direction )
2008-02-18 3:08 am
KE=1/2 mv^2
KE=(1/2)1500(50)^2(1/2)
KE=1875000J
work done=F//s
187000=F(20)
F=937500N
KE=(1/2)1500(50)^2(1/2)
KE=1875000J
work done=F//s
187000=F(20)
F=937500N
2008-02-18 2:58 am
50 是甚麼單位... m/s 嗎?
我假設是了哦~~~
v^2 - u^2 = 2as
0^2 - (50)^2 = 2a(20)
-2500 = 40a
a = -62.5 ms^-2
Therefore, the deceleration of the car is 62.5 ms^-2 .
F= ma
= (1500)(-62.5)
= 93750 N
So, the braking force of the car is 93750 F.
我假設是了哦~~~
v^2 - u^2 = 2as
0^2 - (50)^2 = 2a(20)
-2500 = 40a
a = -62.5 ms^-2
Therefore, the deceleration of the car is 62.5 ms^-2 .
F= ma
= (1500)(-62.5)
= 93750 N
So, the braking force of the car is 93750 F.
參考: me~~
收錄日期: 2021-04-13 15:09:54
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