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Work, Power And Energy
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05/11/2021 10:44 am
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A man drops a 10 kg rock from the top of a 5m ladder. What is its speed just before it hits the ground? What is its kinetic energy when it reaches the ground?
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05/11/2021 10:48 am
Mass of rock = 10 kg
Height of ladder, h = 5m
Initial velocity of rock, u = 0
Final velocity, v
g = 10 m/s2
Using third equation of motion
v2 – u2 = 2gh
v = 10 m/s
KE = \(\frac{1}{2}\) mv2 = 500J