In an action-adventure movie, the hero lifts the 91-kg villain straight upward through a distance of 2.0 m in 0.55 s at a constant speed. What power does the hero produce while doing this?
2007-12-13 01:17:30 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
By definition power P is a rate of flow of energy E
P=E/t
The energy is work done against the gravity and is equal to Pe
E=Pe
Pe=mgh
so
P= mgh/t
P= 91 x 9.81 x 2.0/0.55=3250W
or mechanical horsepower equivalent is
P= 3250/735=4.4 hp
2007-12-13 01:30:38 · answer #1 · answered by Edward 7 · 0⤊ 0⤋
Power = Energy Transferred / Time
Energy Transferred = Gain in G.P.E
G.P.E = mass x gravity accelration x height
G.P.E = 91 x (9.8) x (2) =1783.6 J
Time = 0.55s
Power = 1783.6 / 0.55
Power =3242.909091 Watt
1 Horse power = 735 Watt
3242.909091 / 735 =4.412121211 HP
2007-12-13 01:44:41 · answer #2 · answered by Murtaza 6 · 0⤊ 0⤋
that is strain in engineering.
2007-12-13 01:42:04 · answer #3 · answered by No Special Agenda 7 · 1⤊ 0⤋