1) The total mechanical energy of the rock is:

where U is the gravitational potential energy and K the kinetic energy.
Initially, the kinetic energy is zero (because the rock starts from rest, so its speed is zero), and the total mechanical energy of the rock is just gravitational potential energy. This is equal to

where

is the mass,

is the gravitational acceleration and

is the height.
Putting the numbers in, we find the potential energy

2) Just before hitting the ground, the potential energy U is zero (because now h=0), and all the potential energy of the rock converted into kinetic energy, which is equal to:

where v is the speed of the rock just before hitting the ground. Since the mechanical energy of the rock must be conserved, then the kinetic energy K before hitting the ground must be equal to the initial potential energy U of the rock:

3) For the work-energy theorem, the work W done by the gravitational force on the rock is equal to the variation of kinetic energy of the rock, which is:
Answer:
option a
Explanation:
Size of an atom (diameter) = 10⁻¹⁰ m
There are approximately 10²² atoms in a single drop of water. If they are put in a straight line, the length would be
l = diameter of an atom × number of atoms
l = 10²²× 10⁻¹⁰ m = 10¹² m
Distance between the Sun and the Earth is 1.47 × 10¹¹ m. The calculated length is greater than the distance between the Sun and the Earth.
Thus, option a is correct.
<span>LOCATION Z, because it is only 2 away from the coast.
The rest are farther inland
hope this helps</span>
Hello There!
The resistance of a conductor depends on all of the following except mass.
Mass wouldn't affect the resistance in any way.
Hope This Helps You!
Good Luck :)
- Hannah ❤
Answer
Given,
Time to hear the clap = 14.4 s
speed of the light = 3 x 10⁸ m/s
Speed of sound = 343 m/s
a) distance where lightning strike
D = s x t
D = 14.4 x 343
D = 4939.2 m
b) No, we do not need to know the value of speed of light. Because we need to calculate the distance where we hear the sound. To calculate that we need to know the speed of sound.