A) Water is moving from a point of bigger height to a point of a lower height, This changes the kinetic and potential energies of water. Some of the kinetic energy of water is transfered to a waterwheel. This causes water wheel to spin. Spining waterwheel has rotational energy. Also waterwheel is rotating around certain point. This causes friction and there is frictional energy.
B)To light LED we need electric energy. To create electric energy we need a generator. Generator consists of a rotor (a magnet) and a stator (copper wire). If we attach a magnet to waterwheel and a wire somewhere close to waterwheel the electric energy would be induced. This energy can be used to light LED.
External force.
Air resistance, friction, grass rubbing on a rolling ball, etc.
If there is no external force on a moving object, it keeps going.
Forever !
Answer:
Bridget is transferring energy to the bicycle.
The bicycle is using energy to do work.
Bridget has kinetic energy.
The bicycle has potential energy.
The bicycle has mechanical energy.
Explanation:
Energy can be transformed from one form to another. A body possess kinetic energy due to virtue of its motion. Potential energy is possessed by a body due to virtue of its position. mechanical energy is the sum of potential energy and kinetic energy. Nuclear energy is produced when atoms split or two atoms fuse together.
When Bridget is riding bicycle up a hill. Energy involved is both kinetic energy due to motion and potential energy due to gain in height up the hill. Bridget is pedaling, hence he is transferring energy to the bicycle. Bridget is in motion along with the bicycle. Hence, both Bridget and Bicycle have kinetic energy and potential energy. We can say both have mechanical energy. Thus correct options are:
Bridget is transferring energy to the bicycle.
The bicycle is using energy to do work.
Bridget has kinetic energy.
The bicycle has potential energy.
The bicycle has mechanical energy.
The units of G must be C. m³ / ( kg s² )
<h3>Further explanation</h3>
Newton's gravitational law states that the force of attraction between two objects can be formulated as follows:

<em>F = Gravitational Force ( Newton )</em>
<em>G = Gravitational Constant ( 6.67 × 10⁻¹¹ Nm² / kg² )</em>
<em>m = Object's Mass ( kg )</em>
<em>R = Distance Between Objects ( m )</em>
Let us now tackle the problem !
To find unit of Gravitational Constant can be carried out in the following way:

![{[N]}= G\frac{{[kg]}{[kg]}}{{[m^2]}}](https://tex.z-dn.net/?f=%7B%5BN%5D%7D%3D%20G%5Cfrac%7B%7B%5Bkg%5D%7D%7B%5Bkg%5D%7D%7D%7B%7B%5Bm%5E2%5D%7D%7D)
![{[kg ~ m / s^2]}= G \frac{{[kg^2]}}{{[m^2]}}](https://tex.z-dn.net/?f=%7B%5Bkg%20~%20m%20%2F%20s%5E2%5D%7D%3D%20G%20%5Cfrac%7B%7B%5Bkg%5E2%5D%7D%7D%7B%7B%5Bm%5E2%5D%7D%7D)
![G = \frac{{[kg ~ m / s^2]}{[m^2]}} {{[kg^2]} }](https://tex.z-dn.net/?f=G%20%3D%20%5Cfrac%7B%7B%5Bkg%20~%20m%20%2F%20s%5E2%5D%7D%7B%5Bm%5E2%5D%7D%7D%20%7B%7B%5Bkg%5E2%5D%7D%20%7D)
![G = \frac{{[kg ~ m^3 / s^2]}} {{[kg^2]} }](https://tex.z-dn.net/?f=G%20%3D%20%5Cfrac%7B%7B%5Bkg%20~%20m%5E3%20%2F%20s%5E2%5D%7D%7D%20%7B%7B%5Bkg%5E2%5D%7D%20%7D)
![G = \frac{{[m^3 / s^2]}} {{[kg]} }](https://tex.z-dn.net/?f=G%20%3D%20%5Cfrac%7B%7B%5Bm%5E3%20%2F%20s%5E2%5D%7D%7D%20%7B%7B%5Bkg%5D%7D%20%7D)
![\boxed {G = \frac{{[m^3]}} {{[kg ~ s^2]} }}](https://tex.z-dn.net/?f=%5Cboxed%20%7BG%20%3D%20%5Cfrac%7B%7B%5Bm%5E3%5D%7D%7D%20%7B%7B%5Bkg%20~%20s%5E2%5D%7D%20%7D%7D)
The unit of G must be 
<h3>Learn more</h3>
<h3>Answer details</h3>
Grade: High School
Subject: Physics
Chapter: Gravitational Fields
Keywords: Gravity , Unit , Magnitude , Attraction , Distance , Mass , Newton , Law , Gravitational , Constant