Work = (force) x (distance.
The force required to lift the load is its weight.
Weight = (mass) x (gravity)
so Work = (mass) x (gravity) x (distance)
Now Power = (work) / (time)
so Power = (mass) x (gravity) x (distance) / (time)
= (700kg) x (9.8 m/s²) x (2 m) / (0.4 sec)
= ( 700 x 9.8 x 2) / (0.4) (kg-m²/sec²) / (sec)
= ( 34,300 ) (joule) / (sec)
= 34,300 watts .
This is one of those exercises where the math and the physics
are air-tight and bullet-proof but the answer is absurd.
34,300 watts is about 46 horsepower. I don't care how many
Wheaties Power Lifter Paul had for breakfast today, he is NOT
snatching a barbell that weighs 1,543 pounds (0.77 ton !)
to the height of the top of his head in less than 1/2 second !
Answer:
Explanation:
We need the power equation here:
P = W/t where W is work and is defined as
W = F*displacement.
Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:
w = mg so
w = 166(9.8) so
w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:
and isolating the unknown:
so
t = 5.3 seconds
OD because Boyle’s law specifically states
Answer:
In this case, a body of mass 5 kg kept at a height of 10 m. So the potential energy is given as 5 * 10 *10 = 500 J.
