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A ball is falling freely from the height 10 m. On striking the ground its energy decreases 40 %, then how high can it jump?

Answer»


Solution :The potential energy of the ball at the height `10m=mgh`
`=mxx10xx10`
`=(100M)J`
On STRIKING the earth its energy decreases 40 %. So REMAINING energy with the ball = `60% (100m)J`
`=(60)/(100)xx(100m)J`
`=(60M)J`
Suppose, after striking the ball on the ground, it can jump at height up to h., then
`60m=mxxgxxh.`
`therefore 60=10xxh.`
`therefore h.=6m`


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