<h3>
Answer:</h3>
B. (PE)beginning = (KE)end
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of an object is 72.0 kg
- Velocity of the body before it hits the ground is 79.0 m/s
We are required to determine the relationship between the potential energy and kinetic energy before the fall.
- When an object is at the highest point, it has maximum potential energy and minimum kinetic energy.
- This is because potential energy is directly proportional to the height of an object above the earth's surface.
- On the other hand, when an object attains the highest speed it has maximum kinetic energy and minimum kinetic energy.
In this case;
- The velocity of the object when hitting the ground is maximum and thus the object will have maxim,um kinetic energy.
- As the object falls towards the ground the potential energy is being converted to kinetic energy.
- Therefore, the potential energy at the beginning will be equal to the kinetic energy at the end when the object is on the ground.
- We can therefore, conclude that, (PE)beginning = (KE)end
<h2>
Option 1 is the correct answer.</h2>
Explanation:
Power of heater, P = 1790 W
Time used, t = 24 hours = 24 x 60 x 60 = 24 x 3600 s
We have the equation
![\texttt{Power}=\frac{\texttt{Energy}}{\texttt{Time}}](https://tex.z-dn.net/?f=%5Ctexttt%7BPower%7D%3D%5Cfrac%7B%5Ctexttt%7BEnergy%7D%7D%7B%5Ctexttt%7BTime%7D%7D)
We need to find energy,
Substituting
![\texttt{Power}=\frac{\texttt{Energy}}{\texttt{Time}}\\\\1790=\frac{\texttt{Energy}}{24\times 3600}](https://tex.z-dn.net/?f=%5Ctexttt%7BPower%7D%3D%5Cfrac%7B%5Ctexttt%7BEnergy%7D%7D%7B%5Ctexttt%7BTime%7D%7D%5C%5C%5C%5C1790%3D%5Cfrac%7B%5Ctexttt%7BEnergy%7D%7D%7B24%5Ctimes%203600%7D)
Energy = 1790 x 24 x 3600 J
Option 1 is the correct answer.
Answer:
And unless people interfere, thermal energy — or heat — naturally flows in one direction only: from hot toward cold. Heat moves naturally by any of three means. The processes are known as conduction, convection and radiation. Sometimes more than one may occur at the same time.
Answer:
<h2>
GRAVITY</h2>
Explanation:
When an object is dropped in the air , it experiences free fall.
Free fall is a special type of motion in which the only force acting upon an object is gravity. They do not encounter a significant force of air resistance
Potential Energy = Mass * Gravitational Constant * Height
What We Don't Know: Potential Energy
What We Know:
Mass
Gravitational Constant (9.8 m/s)
Height
Ep = mgh
Ep = 4 * 9.8 * 2
Ep = 78.4 Joules
The Potential Energy of the Rock is 78.4 Joules, based on the given information! Hope this helps you!