The equation for potential energy is denoted as;
Pe = mgh,
where m = the mass, g = acceleration due to gravity, and h = vertical height of the apple. We are given the units for everything but height, which is also what we are solving for. We can then algebraically rearrange our initial equation to solve for h;
h = (Pe)/(mg)
Plug in your given units, and solve!
Post-check:
h = Pe/mg
h = 175J/(0.36g)(-9.81m/s^2)
h = appr. 49.5 meters
Note: Potential energy is a vector quantity; the displacement of the apple will be a negative number, but the distance itself, a scalar quantity, will be the absolute value of that.
Answer:
The correct answer to the question is objects have zero acceleration.
Explanation:
Before answering the question, first we have to understand dynamic equilibrium .
A body moving with uniform velocity is said to be in dynamic equilibrium if the net external forces acting on the body is zero. Hence, the body is under balanced forces.
If the external forces acting on a body is not balanced, then the body will accelerate which will destroy its equilibrium condition. Hence, the necessary and sufficient condition for a body to be in dynamic equilibrium is that the forces are balanced.
When a body is in dynamic equilibrium, the body moves with uniform velocity along a straight line unless and until it is compelled by some external unbalanced forces.
Hence, the rate of change of velocity or acceleration of the body will be zero.
<span>Match the basic components of a nuclear reactor with their descriptions.
1. slows down neutrons
moderator - This is the substance that slows down fast neutrons and makes them slow neutrons which are easier to capture by the atomic nuclei so that the fission reaction can continue.
2. absorb emitted neutrons
control rods - These are rods made up of a substance that easily absorbs neutrons. Their purpose is to slow down or shut down the reaction.
3. mass of unstable atoms
nuclear fuel - The entire point of a nuclear reactor is the capture the energy released by the fission of unstable atoms. So this mass of unstable atoms is the fuel for the nuclear reactor.
4. concrete and lead enclosure
shield - This is the enclosure that prevents radiation from escaping into the general environment.
5. energy transfer medium
coolant - Since the purpose of a nuclear reactor is to generate usable energy, the coolant extracts heat from the fissioning core and that heat is generally used to boil water which in turn is used to operate turbines that power electrical generators.</span>
Answer: 7.41 m/s
Explanation: By using the law of of energy, kinetic energy of the brick as it falls equals the potential energy before falling.
Kinetic energy = mv²/2, potential energy = mgh
mv²/2 = mgh
v²/2 = gh
v² = 2gh
v = √2gh
Where g = 9.8 m/s², h = 2.80m
v = √2×9.8×2.8 = 7.41 m/s
