A boulder is raised above the ground, so that its potential energy relative to the ground is 200 J. Then it is dropped. Estimate
1 answer:
Answer:
200 J
Explanation:
In this problem, I assume there is no air resistance, so the system is isolated (=no external forces).
For an isolated system, the total mechanical energy is constant, and it is given by:
where
KE is the kinetic energy
PE is the potential energy
The kinetic energy is the energy due to the motion of the object, while the potential energy is the energy due to the position of the object relative to the ground.
At the beginning, when the boulder is raised above the ground, its height above the ground is maximum, while its speed is zero; it means that all its mechanical energy is just potential energy, and it is:
As the boulder falls down, its altitude decreases, so its potential energy decreases, while the speed increases, and the kinetic energy increases. Therefore, potential energy is converted into kinetic energy.
Eventually, just before the boulder hits the ground, the height of the object is zero, and the speed is maximum; this means that all the energy has now converted into kinetic energy, and we have
Therefore, the kinetic energy just before hitting the ground is 200 J.
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Answer:
She will use one 2 as a subscript.
Explanation:
Nitrogen is a chemical element with the symbol "N" and has an atomic number of 7. Thus, it is found in group (5) of the periodic table and as such it has 5 electrons in its outermost shell. Therefore, nitrogen has two (5) valence electrons.
On the other hand, oxygen has an atomic number of 8 and with the symbol "O."
When nitrogen and oxygen react chemically, they produce a compound known as nitrogen dioxide
In this scenario, Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Therefore, the statement which describes the subscripts she will use to write the chemical formula is, she will use one 2 as a subscript.
Where: 2 represents the subscript of oxygen.
Answer:
W = 735.75[J]
Explanation:
Work is defined as the product of force by distance. Therefore we can use the following equation.
where:
W = work [J] (units of Joules)
F = force [N] (units of Newtons)
d = distance = 3 [m]
But first, we must determine the force that is equal to the product of mass by gravity (weight of the body).