Lifting the barbell, the weightlifter developed an average power of 5.6 kW. Determine the lifting time of the bar
| July 13, 2021 | education
Lifting the barbell, the weightlifter developed an average power of 5.6 kW. Determine the lifting time of the bar if its weight is 250 kg and the lifting height is 2.0 m.
N = 5.6 kW = 5600 W.
m = 250 kg.
h = 2 m.
g = 9.8 m / s ^ 2.
t -?
Power N is the speed of performing mechanical work.
Power N is determined by the formula: N = A / t.
The work is determined by the formula: A = F * S, where F is the force with which the bar is lifted, S is the movement of the bar.
With uniform motion F = m * g, S = h.
A = m * g * h
N = m * g * h / t.
We will find the ascent time by the formula: t = N / m * g * h.
t = 5600 W / 250 kg * 2 m * 9.8 m / s ^ 2 = 1.1 s.
Answer: the time for lifting the barbell by an athlete is t = 1.1 s.
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