A machine which has an energy loss of 10% will have efficiency of
Answer:
90%
Explanation:
if you lose 10% of a 100 you get 90
i just can't get around physics T^T this is the last question i promise, I'd really appreciate the help <3
question; the work one by friction force to stop a car of mass 1000 kg moves with velocity 72km/h is ..........
a) 72 x 10³ J
b) 2 x 10⁴ J
c) 2 x 10⁵ J
d) 4 x 10⁵ J
an explanation for future reference would be great, thank you in advance!
Use the work-energy theorem. The total work W performed on the car as it it slows to a stop is equal to the change in the car's kinetic energy ∆K. So
W = ∆K
W = 0 - 1/2 (1000 kg) (72 km/h)²
W = - (500 kg) (20 m/s)²
W = - 200,000 J = -2 × 10⁵ J
The closest answer would be C, but friction opposes the car's motion so the work would be negative.
The speed of light traveling through an unknown material is 1.98×108 m/s. Given that the speed of light in a vacuum is 3.00×108 m/s, what is the dielectric constant of the unknown material?
The dielectric constant of the unknown material is 2.3.
What is dielectric constant?Dielectric constant is referred as a relative permittivity or amount of charge required to produce one unit of electric flux in a given medium.
Given the speed of light in vacuum c =3 x 10⁸ m/s and the speed of light through an unknown material v = 1.98 x 10⁸ m/s.
The dielectric constant is related to the velocity by the following relation,
v = c/√K
Rearranging for dielectric constant, we get
K = (c/v)²
Substitute the value into the expression ,we get
K =(3 x 10⁸ / 1.98 x 10⁸)²
K = 2.3
Thus, the dielectric constant of the unknown material is 2.3.
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12
9. An empty, massless cube is measured to have all sides equal to 11 cm. It is floating in water and will slowly be filled with sand
that has a density of 3.5 g/cm'. What volume of sand will cause the box to sink?
Answer:
See below ~
Explanation:
An object will sink in water when its density is greater than that of water, which is 1 g/cm³.
Volume of the box is 1331 cm³. (11³)
Maximum mass of sand will be 1331 g. [because 1331/1331 = 1 g/cm³]
Volume of sand = Mass of sand / Density of sandVolume (sand) = 1331/3.5Volume (sand) = 380.29 cm³If the volume of sand is greater than 380.29 cm³, the box will sink in water.
a satellite moves in a circular orbit around the earth at a speed of 5000 ms. determine the satellites altitude above the earths surface
Answer:
G M m / R^2 = m v^2 / R centripetal force = force of attraction
R = G M / v^2 radius of satellite orbit
R = 6.67E-11 * 5.98E24 / 5000^2
R = 6.67 * 5.98 / 25 * 10^7 m = 1.60 * 107 m = 16 * 10^6 m
Radius of earth = 6.37 * 10^6 m
H = R - r = (16 - 6.4) * 10^6 m = 9.6 * 10^6 m
What happens to the amplitude of the resultant wave when two sound waves with equal amplitude constructively interfere? a. it is half than the amplitude of each wave. b. it is twice than the amplitude of each wave. c. it is the mean of the amplitudes of the two waves. d. it is the square of the amplitude of each wave. e. it is zero.
The amplitude of the resultant wave when two sound waves with equal amplitude constructively interfere, will be twice than the amplitude of each wave.
What is a constructive interference?
A constructive interference occurs when two sound waves with equal amplitude moving in the same direction collide which each other, forming a single wave (resultant wave) with a higher amplitude.
Thus, we can conclude that the amplitude of the resultant wave when two sound waves with equal amplitude constructively interfere, will be twice than the amplitude of each wave.
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A dolphin leaps out of the water
at 6.25 m/s at a 45.0° angle.
How far away does it land?
(Unit = m)
x max = (vi² sin 2α) / g
x max = (6.25² sin 90)/10
x max = 39.0625/10 = 3.91 m
The blackbody curve for a star named Zeta is shown below. The most intense radiation for this star occurs in what spectral band?
radio waves
infrared
visible light
microwaves
Answer:Visible lighlight
Explanation:
Can Pineapple be on pizza
Answer:
yes quite a few people love eating Pineapple on pizza
Answer:
yes, if you want pineapple be in pizza
What sport does not require a high level of fitness
A 100 kg object moving at 20 m/s comes to a stop over a distance of 40 m. what is the coefficient of kinetic friction between the object and the ground? (show work please)
Answer:
.5097
Explanation:
Original KE = 1/2 (100)(20)^2 = 20 000 J
the force of friction must work this hard to stop the object in 40 m
Ff *40 = 20 000
Ff = 500 = Fn u u = coeff of kinetic friction
500 = (100)(9.81) u
u = .5097
The kinetic friction coefficient between the object and the ground is 0.5097.
What is kinetic friction?The friction force to normal force ratio experienced by a body moving on a dry, non-smooth surface is denoted by the kinetic friction coefficient k.
Formula :
μk = [tex]\frac{Ff}{Fn}[/tex]
The types and values of the coefficient of friction are determined by the type of resistive force. The coefficient of friction can be determined through experiments such as calculating the amount of power required to overcome friction or calculating the angle at which an object begins to slide off an incline. The kinetic friction coefficient, or k, is the ratio of friction force to normal force felt by a body moving on a dry, uneven surface. Friction can be classified as static, kinetic, deformation, molecular, or rolling. Each one has a different coefficient of friction. Kinetic friction is the force that prevents normal motion after static friction has been overcome.Therefore,
Original KE = 1/2 (100)(20)^2 = 20 000 J
the force of friction must work this hard to stop the object in 40 m
Ff × 40 = 20 000
Ff = 500 = Fnμ μ = coeff of kinetic friction
500 = (100)(9.81) μ
μ = 500/(100 x 9.81)
μ = .5097
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5. A spring balance is used to weigh a fish. The combined mass of the fish and the pan is 1.50
kg. If the spring constant is 1200 N/m. What distance does the spring stretch?
[tex]\\ \rm\Rrightarrow x=\dfrac{2mg}{k}[/tex]
[tex]\\ \rm\Rrightarrow x=\dfrac{2(1.5)(9.8)}{1200}[/tex]
[tex]\\ \rm\Rrightarrow x=\dfrac{3(9.8)}{1200}[/tex]
[tex]\\ \rm\Rrightarrow x=\dfrac{9.8}{400}[/tex]
[tex]\\ \rm\Rrightarrow x=0.0245m[/tex]
2.45cm is distance
The long structure of small intestine is accommodated in small space within our body. Comment.
Can someone please answer this, ill give you brainliest Would be very appreciated.
Water cycle basically involves the change of water into liquid to vapour and again to liquid states through a cyclic manner .
The answers are
EvaporationTranspirationCondensationprecipitationrunoffseapageground water2 Using the formula GPE = mxgxh, what are
you solving for?
A. Potential Energy
B. Kinetic Energy
C. Electromagnetic Energy
D. Mass Energy
Answer:
A
Explanation:
THAT is th equation for Potential Energy
What is the magnitude of the force needed to keep a 60. -newton rubber block moving across level, dry asphalt in a straight line at a constant speed of 2. 0 meters per second?.
Answer:
A force of μk⋅60N is needed to keep a 60-newton rubber block moving across level, dry asphalt in a straight line at a constant speed.
Explanation:
What's the potential energy for
m= 0.5kg
g=98.1
h=1.5
Answer:
7.36 j
Explanation:
PE = m g h so just mutiply the given values .5 * 9.81 *1.5 = 7.36 j
(assuming 1.5 is in meters)
3
What increase in temperature will result if 225.0 g of copper absorbs 5000 J of
heat energy? The specific heat of copper is 0.385 J/g °C
Calculate: Q=m XCXAT
(2 points)
57.7 °C
433.125 °C
274.6 °C
22.2 °C
The increase in temperature that will result if 225.0 g of copper absorbs 5000 J of heat energy is 57.72°C.
How to calculate temperature change?The temperature change of a substance can be calculated using the following formula:
Q = m × c × ∆T
Where;
Q = quantity of heat absorbed or releasedm = mass of substancec = specific heat capacity∆T = change in temperature5000 = 225 × 0.385 × ∆T
5000 = 86.63∆T
∆T = 5000/86.63
∆T = 57.72°C
Therefore, the increase in temperature that will result if 225.0 g of copper absorbs 5000 J of heat energy is 57.72°C.
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A boy starts from a car and skateboards 7 meters towards the west, then continues skateboarding 2 meters towards the west. What is the boy
's displacement from the car?
A 5 meters west
B 7 meters west
C7.6 meters east
D 9 meters west
E 6 meters south
A boy pushes a toy car along the floor at a steady speed. Are the forces on it balanced
or unbalanced?
Answer:
the forces are balanced :)
Explanation:
What will happen to the force between 2 charged objects if the mass of one of the charges is doubled and the distance between them is double?
Select the statements that apply in order to complete the model (you can choose multiple answers).
a) the products must equal the reactants.
b) one diatomic oxygen should be removed from the reactant side.
c) one unbonded carbon atom should be added to the product side of the equation.
d) one carbon atom and two oxygen atoms are needed to balance the equation.
e) one carbon dioxide molecule should be added to the product side of the equation.
The statement a,d and e are correct. The chemical equation must be balanced.
What is a chemical reaction ?One or more compounds, known as reactants, are transformed into one or more distinct substances, known as products. Such a process is known as a chemical reaction.
The given equation is;
[tex]\rm CH_4+2O_2 \arrow \rightarrow CO_2+2H_2O[/tex]
The statements that apply in order to complete the model is;
a) The products must equal the reactants.
d) One carbon atom and two oxygen atoms are needed to balance the equation.
e) One carbon dioxide molecule should be added to the product side of the equation.
Hence, statement a,d and e are correct.
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What are the potential advantages and disadvantages of a major shift from the hard or traditional path of energy development to the soft or visionary path
Answer: Advantages of following the soft path, the argument here is alternative sources of power such as hydropower, geothermal energy , wind energy , and photovoltaic cells must be developed. This provides a alternative source to remain in a healthy environment and also function as the society we currently live in using the hard path. Disadvantages of following the hard path result with future generations fearing over the irreversible damage of climate change and the damage done to our atmosphere. The hard path argue that we should continue to operate in the future as we have in the past, except more efficiently. This is close to impossible and will only continue the negative effects the hard path( the path we have been following) results in. The major shift determines the outcome of this world, the futures worries or reliefs and ultimately the survival of humans.
What is the speed of light in quartz
Answer:
Approximately 2.06⋅108 meters per second.
Explanation:
PLEASE HELP ME I ATTACHED A SCREEN SHOT PLS SOLVE ASAP
Answer:
B. Negative acceleration means this car is slowing down.
Explanation:
for the other screenshot
Average acceleration = change in velocity /change in time.
[a = ∆V/∆t] —this the formula.
NOTE:
u = initial velocity (velocity it started with)
v = final velocity (velocity it ended with)
t = time {the time you were given)
a = acceleration.
listing out our givens:
u =o —(the unit is m/s)
v = 40 —(the unit is also m/s)
t = 0.08 —(the unit is s) "s" means second(s).
Soo
a = 40-0 / 0.08 = 500 m/s² ( unit for velocity is m/s²)
( Remember when using the formula we subtract the initial from the final velocity.........I mean we remove the initial from final) if not you will get a negative answer or wrong answer).
also note: final velocity is always bigger in value than initial velocity EXCEPT it is in deceleration meaning for example a car that was speeding is gradually stopping then initial (the one it started with) will be bigger than the one it ended with (because as it gradually stops the speed reduces).
VELOCITY is speed in a specified direction.
you're super free to ask any questions
Good luck ✅.
Take the mechanical equivalent of heat as 4 J/cal. A 10-g bullet moving at 2000 m/s plunges
into 1 kg of paraffin wax (specific heat 0.7 cal/g ·C◦). The wax was initially at 20◦ C. Assuming
that all the bullet’s energy heats the wax, its final temperature (in ◦ C) is:
A. 20.14
B. 23.5
C. 20.006
D. 27.1
E. 30.23
Assuming that all the bullet’s energy heats the paraffin, its final temperature is 27.1 degree C. The correct option is D.
What is temperature?Temperature is the degree of hotness and coldness of the material.
The energy of the bullet E = 1/2 mv²
E = 1/2 x 10 x 10⁻³ x (2000)²
E = 2 x 10⁴ J
This heat is used in heating the paraffin
E = m x c ΔT = m x c (Tfinal -Tinitial)
2 x 10⁴ J = 1 x 2.8 x 10³ x (Tfinal -20)
Tfinal = 27.1°C
Thus, the final temperature is 27.1 degree C. The correct option is D.
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The sun will spend most of its lifetime in which stage?.
8. What force is needed to accelerate an elevator upward at a rate of 2m's if the mass of the
elevator is 2,350kg
Answer:
F = M a
F = 2350 kg * 2 m/s^2 = 4700 Newtons
That is in addition to the force of
F = 2350 * 9.8 m/s^2 = 23,030 N needed for a stopped elevator
Which of the following is correct for speed?
A vector
Depends on Distance
Unit is a meter/second (m/s)
A vector
Depends on Displacement
Unit is a meter/second (m/s)
A scalar
Depends on Distance
Unit is a meter/second (m/s)
A scalar
A
Depends on Displacement
Unit is a meter/second (m/s)
Answer:
Speed is a "scalar" quantity
(C) is the correct answer
An object could travel at 10 m/s to some point and then return to the origin at 10 m/s for an average speed of 10 m/s, however it's displacement over that time would be zero for a net velocity of zero.
Select the correct answer from each drop-down menu. andrew pokes a marble, and the marble rolls down a ramp. the marble moves with speed. which forces are acting on the marble in this situation? when andrew pokes the marble, he gives it force. as the marble rolls down the ramp, force pulls it down. the movement of the marble is slowed down by from the ramp.
A net forward force as well as gravitational force pulls the marble downwards whereas frictional force slows it down.
What is a force?A force is an agent which causes a change in the motion or state of an object.
Forces are of two types:
Contact forces andNon-contact forcesAndrew applies force on the marble causing it to move.
When Andrew pokes the marble, he gives it net forward force. As the marble rolls down the ramp, gravitational force pulls it down.
The movement of the marble is slowed down by frictional force from the ramp.
Therefore, a combination of applied force and gravitational force moves the marble forward, while frictional force slows it down.
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Answer:
Applied, Gravitational, and Frictional.
Explanation
hope it helps :)