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How much work must be done to stop a 1800 kg vehicle travelling at 30m/s???

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noobcakes4603 | Student, Grade 9 | Salutatorian

Posted June 1, 2012 at 5:57 AM via web

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How much work must be done to stop a 1800 kg vehicle travelling at 30m/s???

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thilina-g | College Teacher | (Level 1) Educator

Posted June 1, 2012 at 7:20 AM (Answer #1)

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If we should stop the vehicle we should make its kinetic energy zero. That means we have to do a work equal to its kinetic energy against its motion.

Therefore work done  `= W`

`W = K_E`

`W = 1/2 mv^2`

`W = 1/2 xx 1800 xx 30^2 J`

`W = 900 xx 900 J`

`W = 810000 J`

`W = 810 kJ`

 

Therefore the work we have to in order to stop the vehicle is 810 kJ.

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