Answer:
Work done, W = 2675.4 J
Given:
mass, m = 70.0 kg
height, H = 3.90 m
Solution:
According to the question, as the person jumps the stairs up, there is an increase in the potential energy of the person which is provided by the work done in climbing the stairs and is given by:
Work done, W = mgH
where
g = acceleration due to gravity = ![9.8 m/s^{2}[tex][tex]W = 70.0\times 9.8\times 3.90 = 2675.4 J](https://tex.z-dn.net/?f=9.8%20m%2Fs%5E%7B2%7D%5Btex%5D%3C%2Fp%3E%3Cp%3E%5Btex%5DW%20%3D%2070.0%5Ctimes%209.8%5Ctimes%203.90%20%3D%202675.4%20J)
Using the given equation you get:
E = 1.99x10^-25 / 9.0x10^-6
Divide 1.99 by 9.0: 1.99/9.0 = 0.22
For the scientific notation, when dividing subtract the two exponents:
25 -6 = 19
So you now have 0.22 x 10^-19
Now you need to change the 0.22 to be in scientific notation form:
2.2 x 10^-20
The answer is B.
<span>So we want to know why is there a difference between the force of gravity on the Moon and the force of gravity of the Earth. So the gravitational force between two objects depends on the masses of both objects. That can be seen from Newtons universal law of gravity. F=G*m1*m2*(1/r^2). So lets say we are holding an object of mass m=1kg on a height r=1m on the Moon and we are holding the same object on the Earth also on the same height of r=1m. The Gravitational force on the Earth will be Fg=G*M*m*(r^2) where M is the mass of the Earth. The force between the moon and that object will be Fg=G*n*m*(r^2), where n is the mass of the moon. Since mass of the Moon is much smaller than mass of the Earth, The gravitational force between the Moon and that body will be almost 6 times smaller than the gravitational force between the Earth and that body. So the correct answer is B. </span>
