According to a FIR in police station, car A was at rest waiting for a red light at a crossing when it was hit by similar car B from rear side. Both cars had then hard brekes on, and from their skid marks it is surmiesed that they skidded together about 8m in the original direction of travel before coming to rest. Assuming a stopping force of about 0.4 times the combined weights of the cars. the speed of car B just before the collision is approximately `[g=10 m//s^(2)]`
A
8m/s
B
4m/s
C
16 m/s
D
32 m/s
Text Solution
Verified by Experts
The correct Answer is:
C
`S=8,v=0,a=-(0.4)g=-4` `rArru=sqrt(2xx4xx8)=8=` velocity after collision and velocity after collision and velocity before collision be `v_(0)` 2mu=`mv_(0)` `rArr=v_(0)=16 m//s`
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