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The mass of a ball is 18 kg. On Earth when thrown up it rises to 10 m. If it is thrown...

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luissmith | Student, Grade 9 | eNoter

Posted June 5, 2013 at 5:58 AM via web

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The mass of a ball is 18 kg. On Earth when thrown up it rises to 10 m. If it is thrown in the same way on the Moon how high will it rise. g = 10 on Earth and 2 on Moon.

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 5, 2013 at 6:03 AM (Answer #1)

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The mass of the ball is 18 kg. Acceleration due to gravity on the Earth is 10 m/s^2 and on the Moon it is 2 m/s^2. The gravitational potential energy of an object at a height h is equal to PE = m*g*h where m is the mass of the object, g is the acceleration due to gravity.

When the ball is thrown on Earth it rises to 10 m. The energy expended in throwing the ball up is equal to 10*18*10 = 1800 J. If the ball is thrown in a similar fashion, i.e. by expending 1800 J, on the Moon it, rises to a height h where 1800 = 18*2*h or h = 50

The ball rises to a height of 50 m on the Moon.

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