Lifting a mass to a height, you give it gravitational potential energy of
(mass) x (gravity) x (height) joules.
To give it that much energy, that's how much work you do on it.
If 2,000 kg gets lifted to 1.25 meters off the ground, its potential energy is
(2,000) x (9.8) x (1.25) = 24,500 joules.
If you do it in 1 hour (3,600 seconds), then the average power is
(24,500 joules) / (3,600 seconds) = 6.8 watts.
None of these figures depends on whether the load gets lifted all at once,
or one shovel at a time, or one flake at a time.
But this certainly is NOT all the work you do. When you get a shovelful
of snow 1.25 meters off the ground, you don't drop it and walk away, and
it doesn't just float there. You typically toss it, away from where it was laying
and over onto a pile in a place where you don't care if there's a pile of snow
there. In order to toss it, you give it some kinetic energy, so that it'll continue
to sail over to the pile when it leaves the shovel. All of that kinetic energy
must also come from work that you do ... nobody else is going to take it
from you and toss it onto the pile.
yes she is very safe inside
Answer:
The box will experience an acceleration.
Explanation:
Here, 2 N and 3 N forces are acting opposite to each other. In this case, the net force experience by the box would be (3-2)N = 1 N towards right. Since acceleration is directly proportional to the net force, therefore the box will experience an acceleration.
<h2>
Weight of astronaut 2450 miles above the Earth is 80.38 pounds</h2>
Explanation:
Given that gravitational force, F, between an object and the Earth is inversely proportional to the square of the distance from the object and the center of the Earth.
Where F is gravitational force between an object and the Earth, r is the distance from the object and the center of the Earth and k is a constant.
Radius of Earth = 4000 miles
In case 1 an astronaut weighs 209 pounds on the surface of the Earth,
Now we need to find weight of astronaut 2450 miles above the Earth
r = 4000 + 2450 = 6450 miles
Weight of astronaut 2450 miles above the Earth is 80.38 pounds
