Answer:
Explanation:
It’s because of gravitational potential energy, the higher the object is from the ground, the more potential energy due to gravity
A CFL bulb has an efficiency of 0.42 and a imput of 14W. what is the output power
I really need help.
Answer:
The output power is 5.88 W.
Explanation:
We have,
Efficiency of CFL bulb is 0.42
Input power is 14 W
It is required to find the output power. The ratio of output power to the input power is called efficiency. It is given by :
[tex]\eta=\dfrac{P_o}{P_i}[/tex]
[tex]P_o=\eta\times P_i\\\\P_o=0.42\times 14\\\\P_o=5.88\ W[/tex]
So, the output power is 5.88 W.
An ice skater spins at 2.5 rev/s when his arms are extended. He draws his arms in and spins at 10.0 rev/s. By what factor does his moment of inertia change in the process?
Answer:
The moment of inertia decreased by a factor of 4
Explanation:
Given;
initial angular velocity of the ice skater, ω₁ = 2.5 rev/s
final angular velocity of the ice skater, ω₂ = 10.0 rev/s
During this process we assume that angular momentum is conserved;
I₁ω₁ = I₂ω₂
Where;
I₁ is the initial moment of inertia
I₂ is the final moment of inertia
[tex]I_2 = \frac{I_1 \omega_1}{\omega_2} = \frac{I_1*2.5}{10} \\\\I_2 = 0.25I_1 = \frac{1}{4}I_1[/tex]
Therefore, the moment of inertia decreased by a factor of 4
A charge of 80 coulombs passes through a circuit in 5 seconds. What is the current through the circuit?
Answer:
I = 16amp
Explanation:
Charge coulomb ( Q ) = It
Where I =current in ampere
t = time = 5 seconds
80 = I × 5
I = 80/5
I = 16amp
The current through the circuit will be I = 16amp
Meeta used an elastic tape to measure the length of her window to stitch a curtain. Do you think she will be able to stitch a curtain of correct measurement? Yes/No . Give scientific reason in detail, also explain the correct method to measure the length of her window.
Answer:
No
Explanation:
She will not be able to measure the length of her window accurately due to instrumental error from her choice of instrument. The elastic nature of her tape would alter the measurement because it will stretch as she is taking her readings, thus reducing the true measurement of the length of her window.
To measure the length of her window, she could use an inelastic tape rule or a metre rule. These instruments would eliminate instrumental error.
30
. Which of the following represents the
statement "The difference of two square
numbers is positive
Answer:
In mathematics, the difference of two squares is a squared (multiplied by itself) number subtracted from another squared number. Every difference of squares may be factored according to the identity. in elementary algebra.
Explanation:
How do oxbow lakes form?
Explanation:
It is formed when a river creates a meander, due to the river's eroding bank. After a long period of time, the meander curves and cuts, forming an oxbow lake.
Answer:
c
Explanation:
I did the test and got it right. I promise :)
The acceleration of gravity means that for each second that passes, falling
objects move 9.8 meters.
A. True
B. False
Answer:
B.
Explanation:
There are many factors that go into the speed that an object drops. For example, aerodynamics, weight, and other things.
A force of 1000 Newtons is used to push a box on a flat floor. It accelerated at a rate of 5 m/s2. What is the mass of the wagon?
Answer:
67.56kg
Explanation:
Fapp+mg = ma
Fapp= applied force
mg = reactional force
g = acceleration due to gravity
Where g = 9.8m/s^2 a= 5 m/s2, Fapp= 1000N.
1000N = ma + mg
1000N = m( a+g )
1000N = m ( 5+9.8)
1000N = m×14.8
m = 1000÷14.8
m = 67.56kg.
Hence the mass of the wagon will be 67.56kg
Two types of emission spectra line spectra and continuous spectra
True
False
The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.
Answer:
Pmax = 67.5 KN
Explanation:
We need to calculate the maximum allowable value of P for both aluminum and steel bars.
FOR STEEL BARS:
Since,
(σallow)st = (Pmax)st/A
where,
(σallow)st = maximum allowable stress of steel bar = 200 MPa = 2 x 10⁸ Pa
A = Cross-sectional area of steel bar = 450 mm² = 0.45 x 10⁻³ m²
(Pmax)st = Maximum allowable force for steel bar = ?
Therefore,
2 x 10⁸ Pa = (Pmax)st/0.45 x 10⁻³ m²
(Pmax)st = (2 x 10⁸ Pa)(0.45 x 10⁻³ m²)
(Pmax)st = 9 x 10⁴ N = 90 KN
FOR Aluminum BARS:
Since,
(σallow)al = (Pmax)al/A
where,
(σallow)al = maximum allowable stress of Al bar = 150 MPa = 1.5 x 10⁸ Pa
A = Cross-sectional area of Aluminum bar = 450 mm² = 0.45 x 10⁻³ m²
(Pmax)al = Maximum allowable force for Aluminum bar = ?
Therefore,
1.5 x 10⁸ Pa = (Pmax)al/0.45 x 10⁻³ m²
(Pmax)al = (1.5 x 10⁸ Pa)(0.45 x 10⁻³ m²)
(Pmax)al = 6.75 x 10⁴ N = 67.5 KN
Since,
(Pmax)al < (Pmax)st
Therefore,
The maximum allowable force will be:
Pmax = (Pmax)al
Pmax = 67.5 KN
Ski lift carry people along 150 m cable up the side of a mountain. Riders are lifted a total of 75 m in elevation. What is the ideal mechanical advantage of the ski lift?
Ideal Mechanical Advantage (IMA) can be found by using the formula:
IMA = ID/OD
ID = Input Distance
OD = Output Distance
In the question, we are given:
ID = 150
OD = 75
Now, solve the expression with what we have.
IMA = 150/75
IMA = 2
Therefore, the IMA is 2.
Best of Luck!
Which phrases describe all the outer planets’ motion? Select two options.
no rotation
fast rotation
slow revolution
opposite revolution
north to south rotation
Answer:
Fast rotation
Slow revolution
Explanation:
Solar system has 8 planets. 4 inner rocky planets - Mercury, Venus, Earth and Mars and 4 outer gaseous planets - Jupiter, Saturn, Uranus and Neptune. The outer planets have few common features.
They are gaseous. There period of revolution is larger than the inner planets which means that they have slow revolution about the Sun. One day on the outer planets is smaller than the inner planets which means they have fast rotation.
For example, Jupiter has revolves around sun in 11.86 Earth years and rotates about axis in 9.8 Earth hours. Uranus revolves around sun in 84 Earth years and rotates on its axis 17.9 Earth hours.
Answer:
Fast rotation
Slow revolution
Explanation:
did the test
Chef Andy tosses an orange in the air, then catches it again at the same height. The orange is in the air for 0.75\,\text s0.75s0, point, 75, start text, s, end text. We can ignore air resistance.
Answer:
3.68 m/s
Corrected question;
Chef Andy tosses an orange in the air, then catches it again at the same height. The orange is in the air for 0.75 s. We can ignore air resistance. What was the orange's velocity at the moment it was tossed into the air?
Explanation:
Applying the equation of motion;
v = u + at. ....1
Where
u = initial speed
v = final speed
a = acceleration
t = time taken
Given;
Total time of flight t = 0.75s
Acceleration due to gravity g = 9.8 m/s^2
Considering the first phase of flight, during the upward motion to the maximum height. The final velocity at the maximum height is zero and the time of flight of the phase is equal to half of the total flight time.
v1 = 0
t1 = t/2 = 0.75/2 =0.375s
From equation 1;
v1 = u - gt1
Substituting the values;
0 = u - 9.8(0.375)
Solving for u;
u = 9.8(0.375)
u = 3.675
u = 3.68 m/s
Initial velocity = 3.68 m/s
Which is closer to the Sun—Mercury or the Earth? A. They are the same distance from the Sun. B. The Earth is closer to the Sun than Mercury is. C. Mercury is closer to the Sun than the Earth is. D. The distance from the Earth to the Sun cannot be determined.
Answer:
the answer is C
Explanation:
I know because mercury is the first planet closest to the sun
In an inelastic collision, which of the following statements is always true?
[A] Kinetic energy is conserved in the collision.
[B] Momentum is conserved in the collision.
[C] After the collision, the objects always merge into one.
[D] The collision takes more that 1 second to complete.
Answer: A
Explanation:
A
A starter pistol is fired 150m away from the spectators who hear the gun 0.5s after they see it fired. How fast does sound travel?
(Please help!)
Answer:
300m/s
Explanation:
speed = distance/time
150/0.5
what is the force when an object exerts 15 pascal pressure on a square surface of side 5 meters
Answer:375N
Explanation:
pressure =15 pascal
Length =5 m
Area=length x length
Area=5 x 5
Area=25 m^2
Force=pressure x area
Force=15 x 25
Force=375N
Calculate the energy that 1.5 kg of mass contains
Answer:
[tex]4.5(10)^8[/tex] joules
Explanation:
Mass–energy equivalence is the principle that says that anything that has mass has an equivalent amount of energy. Converse is also true.
The relation between energy and mass is given by [tex]E=mc^2[/tex]
Here, E denotes energy, m denotes mass and c denotes speed of light
Mass [tex](m)=1.5\,\,kg[/tex]
Speed of light (c) = 3 × [tex]10^8[/tex] m/s
Therefore,
[tex]E=1.5(3)(10)^8=4.5(10)^8[/tex] joules.
The S.I. unit of energy is joules which is equal to [tex]1\,\,kg\,\,m^2/s^2[/tex]
Animals have different types of respiratory systems depending on the environment of their habitat. Fish live in the water and use gills to breathe. Humans who live on land, breathe air through their lungs. Identify the similarities between lungs and gills.
Answer:
1. Both are respiratory organs found in vertebrates.
2. Both enable the inhalation of oxygen and exhalation of carbon dioxide in the bodies of their host.
3. Respiratory membranes present in both make the exchange of gases easier.
4. Blood vessels found around them enable the breathing process.
Explanation:
Gills are respiratory organs which can be found in animals that live in water. These include fishes, amphibians like frogs, anthropods like insects, and annelids like worms. Gills are surrounded by respiratory membranes known as gill lamellae which have a large surface area that makes breathing easier. Blood vessels also are found around gills.
The lung is also a respiratory organ found in humans. It runs from a windpipe known as the trachea and branches into bronchi which contain the bronchioles. Alveoli ducts contain alveoli sacs and then alveoli which are membranes that enable the breathing process.
Both are similar because they are respiratory organs found in animals with backbones. They are surrounded by blood vessels and membranes that make the breathing process easier.
what are polarized waves
Answer:
A light wave that is vibrating in more than one plane is referred to as unpolarized light.
Explanation:
how do braces protect you while doing sports
Answer:
they don't, if you get hit in the face then the brackets are gonna rub up against the inside of your mouth then you'll bleed
Explanation:
2. Identify which condition is NOT a chronic disease
a. diabetes
c. heart
b. cancer
d. cold
3. Identify the single most important component of healt
Answer:
cold
Explanation: a cold is minor the rest are major
Which equation is used to calculate the magnetic force on a charge moving in a magnetic field?
F = |g|vBcose
F = |g|vBsine
F = 1g|Bcose
F = 1g|Bsine
Answer:
B
Explanation:
canadas largest trading partner is
Answer:
united states
Explanation:
give brainiest please
Jenny and Fred both play a long note on their trombones. A stationary observer hears the sound increasing and decreasing repeatedly in loudness. Which of these must be true?
A.The sound waves from the two trombones have slightly different frequencies.
B. The sound waves from the two trombones have the same frequency.
C. The sound waves from the two trombones have slightly different amplitudes.
D. The sound waves from the two trombones have the same wavelength.
E. The sound waves from the two trombones have slightly different velocities.
Answer:
A.The sound waves from the two trombones have slightly different frequencies.
Explanation:
This is because, a difference in frequency of waves from two different sources would result in either constructive or destructive interference of the waves. Thereby, causing the observer to hear the sound increasing or decreasing.
Answer:
A.The sound waves from the two trombones have slightly different frequencies.
This diagram shows a baseball’s motion. Which statement is best supported by the diagram?
a
Maximum Gravitational potential energy is at point R.
b
Kinetic energy becomes potential energy between points P and Q.
c
Kinetic energy becomes potential energy between points R and S.
d
Maximum kinetic energy is at point R.
Answer:
A
Explanation:
maximum gravitional potential energy is at point R
A skier reaches the end of a 0.9 km track in 1.5 hours, at what speed does it travel?
(Please help,I need the answer as soon as possible)
Speed = Distance/Time
S = D/T
D = 0.9Km, T = 1.5hours,
S = 0.9/1.5
S = 0.6 m/s
hope it helps!
Answer: Speed =
distance = 0.9 * 1000 = 900 metres, because speed is measured in m/s so the km has to be converted to m
time = 1.5 * 60 = 90 seconds , because speed is measured in m/s so the time in minutes(m) has to be converted to seconds(s)
Speed =
= 10m/s
Read more on Brainly.com - https://brainly.com/question/11367821#readmore
Explanation: I don't know what this is but this is what I found and I hope it's helpful
What is the critical angle for glass when the refractive index is 1.45
Answer:43.6°
Explanation:
Refractive index=n=1.45
Critical angle=c
n=1/sinc
1.45=1/sinc
Cross multiply
1.45sinc=1
Divide both sides by 1.45
(1.45sinc)/1.45=1/1.45
sinc=0.6897
c=sin(inverse)(0.6897)
c=43.6°
Critical angle is 43.6°
what type of stars can collapse in a supernova explosion and become neutron stars
Answer:
red supergiants can
At a grocery store, 20 fl oz of brand A vitamin
water is sold for $0.95. What is the unit price of
the vitamin water per ounce, to the nearest cents?
Answer:
0.05 cents per fl oz
Explanation:
0.95 divided by 20
0.0475 to the nearest cent 0.05
