What is the potential energy of a 35 kg child sitting at the top of a slide that is 3.5 m above the ground?
What is her kinetic energy if she moves down the slide at a speed of 5.0 m/s?
Answer (3)
PE = mgh = (35)(9.8)(3.5) = answer
KE = (1/2)mv^2 = (1/2)(35)(5)^2 = answer
m = 35 k g h = 3.5 m v = 5 m / s g = 10 m / s 2 E p = m g h E p = 35 k g ⋅ 10 m / s 2 ⋅ 3.5 m = 1225 s 2 k g m 2 = 1225 J E k = 2 m v 2 E k = 2 35 k g ⋅ ( 5 m / s ) 2 = 2 35 k g ⋅ 25 m 2 / s 2 = 437.5 s 2 k g m 2 = 437.5 J
The potential energy of the 35 kg child at the top of the slide is 1225 joules. When the child moves down the slide at a speed of 5.0 m/s, her kinetic energy is 437.5 joules.
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