Energy to lift something =
(mass of the object) x (gravity) x (height of the lift).
BUT ...
This simple formula only works if you use the right units.
Mass . . . kilograms
Gravity . . . meters/second²
Height . . . meters
For this question . . .
Mass = 55 megagram = 5.5 x 10⁷ grams = 5.5 x 10⁴ kilograms
Gravity (on Earth) = 9.8 m/second²
Height = 500 cm = 5.0 meters
So we have ...
Energy = (5.5 x 10⁴ kilogram) x (9.8 m/s²) x (5 m)
= 2,696,925 joules .
That's quite a large amount of energy ... equivalent to
straining at the rate of 1 horsepower for almost exactly an
hour, or burning a 100 watt light bulb for about 7-1/2 hours.
The reason is the large mass that's being lifted.
On Earth, that much mass weighs about 61 tons.
Frictional Force is the answer..
Hope it helps
The correct option is B.
Resonance is said to occur when one object which is vibrating at the same natural frequency of a second object forces the second object into vibrational motion. When resonance is achieved a big loud voice is usually heard. Resonance generally requires three conditions to occur:
1. An object that has a natural frequency.
2. A force that is functioning at the same frequency as the natural frequency.
3. Prevention of energy loss.
Okay, first off, the formula for Kinetic Energy is:
<em>KE = 1/2(m)(v)^2</em>
<em>m = mass</em>
<em>v = velcoity (m/s)</em>
Using this formula, we can then calculate the kinetic energy in each scenario:
1) KE = 1/2(100)(5)^2 = 1,250 J
2) KE = 1/2(1000)(5)^2 = 12,500 J
3) KE = 1/2(10)(5)^2 = 125 J
4) KE = 1/2(100)(5)^2 = 1,250 J
