Answer:
P = 24.32 W
Explanation:
The question is, "Two resistors 5 Ω and 10 Ω are connected in parallel with a 9 V power supply. Calculate the output power of the power supply.".
The voltage of the power supply, V = 9 V
Resistor 1, R₁ = 5 Ω
R₂ = 10 Ω
The equivalent of parallel combination of resistors is given by :
[tex]\dfrac{1}{R_{eq}}=\dfrac{1}{R_1}+\dfrac{1}{R_2}\\\\\dfrac{1}{R_{eq}}=\dfrac{1}{5}+\dfrac{1}{10}\\\\R_{eq}=3.33\ \Omega[/tex]
The power of the output is given by :
[tex]P=\dfrac{V^2}{R_{eq}}\\\\=\dfrac{9^2}{3.33}\\\\P=24.32\ W[/tex]
So, the output power is equal to 24.32 W.
1. An atom that loses electrons has a ________________________ charge and an atom that gains
electrons has a ___________________________ charge.
Charged atoms are called ___________________.
2. What is an insulator? Give 4 examples.
3. What is a conductor? Give an example.
4. How can we move electrons from one place to another? What actually causes the electrons to
move?
5. Static electricity is ______________________________________________________________________
_______________________________________________________________________________________
6. Explain the attraction and repulsion of charges.
7. Why does a balloon stick to the wall?
8. Why does your hair stand up when you take off your hat?
9. Why do you get a shock when you walk across a carpet?
10. When is static electricity most noticeable and why?
11. State the Principle of Conservation of Charge.
12. The invisible electric force field around charged objects depends on __________________________,
__________________________, and _____________________________.
13. What is the relationship between the charges and the field strength?
What is the relationship between the field strength and the distance between the charges?
1. What is DC?
What is AC?
2. Name 3 ways to get DC.
3. What is an electrical circuit?
4. What is voltage?
What is current?
What is resistance?
What causes heat and light in a wire?
COPY THE TABLE comparing water in a hose-DC-units
5. Which electricity do we use in our homes?
CLICK ON ALTERNATING CURRENT
1. Explain AC.
2. Who invented the light bulb?
3. Who really invented AC?
4. Who discovered the advantages of AC over DC?
5. How is AC made?
6. What is the main advantage of AC over DC?
A.) A gemstone of mass 1.8 kg compresses a scale's spring by 2.6 cm.
Determine the spring constant.
B.) How much would the spring in the previous question compress if a 5.2 kg mass was placed on the scale?
Explanation:
Given that,
Mass, m = 1.8 kg
Compression, x = 2.6 cm
We know that,
Force on spring = weight
So,
[tex]mg=kx[/tex]
Where
k is spring constant
[tex]k=\dfrac{mg}{x}\\\\k=\dfrac{1.8\times 9.8}{2.6\times 10^{-2}}\\\\k=678.46\ N/m[/tex]
(2) If m = 5.2 kg
[tex]x=\dfrac{mg}{k}\\\\x=\dfrac{1.8\times 9.8}{678.46}\\\\x=2.6 \ cm[/tex]
Hence, this is the required solution.
A 45.7 kg woman starts from rest at the bottom of a flight of stairs that has
a total height of 2.54 meters. She reaches the top of the stairs
in 5.00 seconds. How much power does she generate if she is moving at
2.63 m/s at the top of the stairs? Use g = 9.8 m/s2, and only include 3
numbers in your answer.
Answer:
The power generated by the woman is 259 W
Explanation:
Given;
mass of the woman, m = 45.7 kg
initial velocity of the woman, u = 0
total height ascended by the woman, h = 2.54 m
time of the woman's motion, t = 5.0 s
final velocity of the woman, v = 2.63 m/s
acceleration due to gravity, g = 9.8 m/s²
The potential energy of the woman due to the height she ascended;
P.E = mgh
P.E = 45.7 x 9.8 x 2.54
P.E = 1137.564 J
The kinetic energy of the woman due to her final velocity;
K.E = ¹/₂mv²
K.E = ¹/₂ x 45.7 x (2.63)²
K.E = 158.051 J
The total mechanical energy of the woman at the top of the stairs;
M.E = P.E + K.E
M.E = 1137.564 J + 158.051 J
M.E = 1295.615 J
The power generated by the woman;
Power = Energy/time
Power = 1295.615 J / 5 s
Power = 259.123 W
Power = 259 W