a car of mass 400 k travelling at 72 kmph crashes into a truck of mass 400 kg and travelling at 9 kmph in same direction. the car bounces back at a speed of 18 kmph. find the speed of the truck after the impact
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a car of mass 400 k travelling at 72 kmph crashes into a truck of mass 400 kg and travelling at 9 kmph in same direction. the car bounces back at a speed of 18 kmph. find the speed of the truck after the impact
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Answer:
It's 63kmph.
Explanation:
Momentum of the car =28800 kg.m/s
". ". ". truck=3600 kg.m/s
Total momentum of car and truck= 28800+3600
= 32400 kg.m/s
(everything above are of before collision / crash.)
Now after collision/crash.,
Momentum of car= 7200 kg .m/s
Momentum of truck= mass of truck×velocity of the truck.
let velocity of the truck be v.
then ,
momentum= 400 v kg.m/s
Total momentum = 7200+400 v
Now according to the law of conservation of momentum:
Total momentum before=Total momentum after
32400 =7200+400 v
400 v= 32400-7200
400 v=25200
v =25200/400
v=63 m/s
therefore, velocity of the truck after the impact will be 63m/s .
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