Jeff is part of a trekking team. As he climbs a hill, he drops his water bottle, which has a mass of 0.25 kilograms.

The bottle slides down the hill and is moving at a velocity of 14 meters/second the instant it hits the ground. The vertical height from where Jeff dropped the bottle is ? meters. Ignore friction, and use, PE = m * g * h, and g = 9.8 m/s2.

Question

Rene Dunn

Physics

4 August, 14:33

Jeff is part of a trekking team. As he climbs a hill, he drops his water bottle, which has a mass of 0.25 kilograms.

The bottle slides down the hill and is moving at a velocity of 14 meters/second the instant it hits the ground. The vertical height from where Jeff dropped the bottle is ? meters. Ignore friction, and use, PE = m * g * h, and g = 9.8 m/s2.

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Answers (1)

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Juliette Hancock · Answer 1

The kinetic energy of the ball is

KE = 1/2 (0.25) (14) ²

KE = 24.5 J

Equate it to the potential energy of the ball when it's dropped which is

PE = 0.25 (9.81) h

PE = 2.45 h

Equating ...

24.5 = 2.45 h

Solve for h

h = 10 m

The bottle was dropped 10 m above the ground.