If 10kg mass is dropped from a certain height,hits the ground with speed 10m/s. The height will be. Ans=5m. plz explain it?
回答 (2)
2016-06-16 6:12 pm
Take g = 10 m/s²
Initial speed, u = 0 m/s
Final speed, v = 10 m/s
Acceleration, a = 10 m/s²
Height, s = ? m
v² = u² + 2as
10² = 0² + 2 × 10 × s
20s = 100
Height, s = 5 m
Initial speed, u = 0 m/s
Final speed, v = 10 m/s
Acceleration, a = 10 m/s²
Height, s = ? m
v² = u² + 2as
10² = 0² + 2 × 10 × s
20s = 100
Height, s = 5 m
2016-06-16 7:46 pm
Kinetic energy of mass as it hits the ground = ½mv² = ½ * 10 * 10² = 500 joules
By conservation of energy, that 500 J must have been the gravitational potential energy of the object before it was dropped.
Gravitational potential energy = mgh
Therefore:
500 J = 10 kg * 10 m/s² * h
500 = 100h
h = 5 m
By conservation of energy, that 500 J must have been the gravitational potential energy of the object before it was dropped.
Gravitational potential energy = mgh
Therefore:
500 J = 10 kg * 10 m/s² * h
500 = 100h
h = 5 m
收錄日期: 2021-04-18 15:06:45
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