The coefficient of kinetic friction between the box and the floor is 0.323.
By Newton's Law of Motion we understand that an object is at equilibrium if and only if it is at rest or it is moving at constant velocity. If a horizontal force is applied on the box and it is moving, then a force with equal magnitude and opposed to that force must exists, which corresponds to the kinetic friction. Let suppose that the box is moving on a horizontal ground.
The equation of equilibrium for the box is described below:
[tex]\Sigma F = P - \mu_{k}\cdot m\cdot g = 0[/tex] (1)
Where:
[tex]P[/tex] - External force, in newtons.[tex]\mu_{k}[/tex] - Kinetic coefficient of friction, no unit.[tex]m[/tex] - Mass, in kilograms.[tex]g[/tex] - Gravitational constant, in meters per square second.An expression for the kinetic coefficient of friction is derived by clearing the variable in (1):
[tex]\mu_{k} = \frac{P}{m\cdot g}[/tex] (2)
If we know that [tex]P = 38\,N[/tex], [tex]m = 12\,kg[/tex] and [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], then the kinetic coefficient of friction is:
[tex]\mu_{k} = \frac{38\,N}{(12\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)}[/tex]
[tex]\mu_{k} = 0.323[/tex]
The coefficient of kinetic friction between the box and the floor is 0.323.
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What will happen if we increase the friction on a roller coaster?
A. The speed of the roller coaster will increase.
B. The speed of the roller coaster will decrease
C. The speed of the roller coaster will remain constant.
D. The roller coaster will fly away
Answer: B. The speed will decrease.
Explanation:
When you ride a roller coaster, the wheels rub/scrape the rails, creating heat as a result of friction. And friction will slow you down. So increasing the friction on a roller coaster would slow it down.
Answer:
B
Explanation:
Friction opposes motion therefore reducing motion
Which of the following is an example of a luminous object?
Dog
Tree
Candle
Moon
Answer:
Candle
Explanation:
The moon is an illuminated object, while a candle is a luminous object!
Answer:
Candle
Explanation:
I just took the test
An object originally moving at a speed of 20. meters per second accelerates uniformly for 5.0 seconds to a
final speed of 50. meters per second. What is the acceleration of the object?
Answer:
92
Explanation:
What, exactly, is moving across the medium?
Answer:
So waves are everywhere. But what makes a wave a wave? What characteristics, properties, or behaviors are shared by the phenomena that we typically characterize as being a wave? How can waves be described in a manner that allows us to understand their basic nature and qualities?
A wave can be described as a disturbance that travels through a medium from one location to another location. Consider a slinky wave as an example of a wave. When the slinky is stretched from end to end and is held at rest, it assumes a natural position known as the equilibrium or rest position. The coils of the slinky naturally assume this position, spaced equally far apart. To introduce a wave into the slinky, the first particle is displaced or moved from its equilibrium or rest position. The particle might be moved upwards or downwards, forwards or backwards; but once moved, it is returned to its original equilibrium or rest position. The act of moving the first coil of the slinky in a given direction and then returning it to its equilibrium position creates a disturbance in the slinky. We can then observe this disturbance moving through the slinky from one end to the other. If the first coil of the slinky is given a single back-and-forth vibration, then we call the observed motion of the disturbance through the slinky a slinky pulse. A pulse is a single disturbance moving through a medium from one location to another location. However, if the first coil of the slinky is continuously and periodically vibrated in a back-and-forth manner, we would observe a repeating disturbance moving within the slinky that endures over some prolonged period of time. The repeating and periodic disturbance that moves through a medium from one location to another is referred to as a wave.
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Explanation:
In which image below is the angle of refraction the greatest?
Answer:
Explanation:
Angle of refraction is the angle made by refracted ray with the normal at the point of incidence . In this figure , refracted ray has been shown by line having arrow-head . Normal has been shown by broken line .
We observe that in figure D , angle made by refracted ray with normal is greatest . So figure D is the answer.
The image where the angle of refraction is the greatest is the image D
What is the angle of refraction?The angle of refraction is the angle that the refracted ray made with the x-axis.
The higher the angle between the refracted ray and the x-axis, the higher the angle of refraction and vice versa.
From the given diagram, we can see that the image where the angle of refraction is the greatest is the image D
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pls help me i need both answers pls help me this is being timed.
Answer:
it would have to be diagram C OR B
Just like Coke is a type of soda, __________ is a type of ___________.
A.concentration,.equilibrium
B..equilibrium, concentration
C.diffusion, osmosis
D.osmosis. diffusion
Answer:
osmosis diffusionExplanation:
ok it's correct
A 1250 kg Nascar is at the starting line. The race starts and the car reaches a speed of 30
m/s in 10 seconds. What is the force of the car? (Hint: Remember that acceleration
change in velocity / time.)
Answer:
force=1250kg * 30m/s+10
Explanation: it's a change in acceleration
Which of the following non-metals is used as a lubricant in powdered form?
a) Sulphur
b) lodine
c) Graphite
d) Silicon
Answer:
Graphite.
Explanation:
Graphite: "a gray crystalline allotropic form of carbon which occurs as a mineral in some rocks and can be made from coke. It is used as a solid lubricant, in pencils, and as a moderator in nuclear reactors."
The mechanical advantage of a lever is 4 . what does it mean?
Answer:
It means...
Explanation:
The mechanical advantage of a machine is 4. Mechanical advantage MA is the ratio of output (generated by the machine) force to input (applied to the machine) force. So MA = 4 means that for example if you apply 100 N then your machine will multiply that force and generate 400 N.
Answer:
The mechanical advantage of a lever is 4 means that the lever can lift a load which is four times greater than the applied effort.
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Why do we use insulators if they prevent the flow of electricity?
Answer:
letterman is shooting the kids
We use insulators to avoid being electrocuted. electricians use rubber gloves to avoid shock. Cables are insolated with rubber so you can hold them without getting shocked even if it is plugged in.
A student is doing a genetics experiment on beetles. The student breeds a pure green beetle with a pure brown beetle. The student repeats this experiment ten more times. Every time the student performs this cross, all of the offspring are green. What does that mean? A. The gene for green and brown are equally expressed because half the beetle parents have a green phenotype and half the beetle parents have a brown phenotype. B. The gene for green color is dominant over the gene for brown because all the beetle offspring have a brown phenotype. C. The gene for brown color is dominant over the gene for green color because all of the beetle offspring have a brown genotype. D. The gene for green color is dominant over the gene for brown color because all the beetle offspring have a green phenotype.
Answer:
b
Explanation:
bbhbh
The genes for green color are dominant over the genes for brown color because all the beetle offspring have a green phenotype. Therefore, option (D) is correct.
What is phenotype?In biology, a phenotype can be described as the observable characteristics of an organism which is the result of the interaction of environmental factors and genes. These traits involve physical appearances and any traits that we can observe.
The phenotype includes its physiological, biochemical, as well as behavioral properties. Genotype is inherited from the parents while the phenotype can be affected by lifestyle and environmental factors. Environmental factors such as nutrition, temperature, humidity, and mental health of the organism.
For example, flamingoes are white in color but turn pink because of the pigments they need from their diet. Therefore, flamingoes portray how they are affected by environmental factors. The phenotype of an organism changes, accordingly to environmental factors.
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Finding the area of a trapezoid on a velocity versus time graph will tell you
the ——————
of an object.
A. displacement
B. acceleration
C. velocity
D. distance
Describe Kinetic Energy.
please help!!!!!!!!!!!!!!!!!!!!!!
Answer: I'm sure the answer is a.
Explanation: I hope that helped you.
Answer:
Precipitate
Explanation:
6. A total of 135 J of work is done on a gaseous refrigerant as it undergoes compression. If
the internal energy of the gas increases by 114 J during the process, what is the total amount
of energy transferred as heat? Has energy been added to or removed from the refrigerant as
heat?
Answer:
Eh = 21 [J]
Removed as heat.
Explanation:
This is a case of energy conservation, we have to take into account the energies that go in and out of the system. In this case, 135 [J] of energy are entered in the form of work of the compressor to the chamber where the refrigerant is compressed, now of these 135 [J] 114 [J] were used as internal energy, this internal energy is used to increase the pressure and temperature of the refrigerant.
In this way the rest of the energy of the 135 [J] was lost in the form of heat to determine this loss of energy, we simply perform the arithmetic subtraction.
Eh = 135 - 114 = 21 [J]
Eh = 21 [J]
HELP ME !!!
A basketball has a mass of 1 kg and is traveling 12 m/s.
What would happen to the velocity if the momentum of the basketball were cut in half?
It would be doubled.
It would be cut in half.
It would be the same.
It would be tripled.
Answer:
It would be cut in half.
Explanation:
If the momentum of the ball is cut into half, the velocity will also be halved.
The momentum of a body is the amount motion a body possess.
Momentum is given as;
momentum= m x v
Given that;
mass = 1kg
velocity = 12m/s
Now find the momentum;
momentum = 1 x 12 = 12kgm/s
Halving the momentum = 6kgm/s
mass = 1kg
Momentum = 1 x v
6 = 1 x v
v = 6m/s
We see that the velocity reduces by half
Answer:
It would be doubled.
Explanation:
I'm in K12
Is a ball a wheel and axle if so how do you calculate the Mechanical Advantage of the ball? If not what kind of simple machine is a ball?
A car accelerates from 20 m/s to 80 m/s in 5 seconds. What is the
average acceleration of the car?
a 20 m/s2
b 12 m/s2
C 4 m/
d 16 m/s2
Answer:
12m/s2
Explanation:
:D (just a smiley, not answer d)
1.A runner has a displacement of 20 meters in 5 seconds, what is his velocity
during this time?
Answer:
The required velocity of runner is 4m/s.
A battery and a resistor are wired into a circuit. The resistor dissipates 0.30 W. Now two batteries, each identical to the original one, are connected in series with the resistor. What power does it dissipate?
Answer:
1.2 W
Explanation:
Let the value of resistance be R , emf of battery be E
current i = E / R
power = i² R
= E² x R / R²
= E² / R
Given
E² / R = .30
when two batteries are connected
Total emf = 2E
current = 2E / R
Power = ( 2E / R )² x R
= 4 E² / R
= 4 x .30
= 1.2 W .
What is a super dense gravitationally collapsed mass from which no light
can escape called?
1) neutron star
2) pulsar
3) supernova
4) black hole
Se lanza una pelota y regresa al punto de partida 2.5 s después ¿Que altura máxima alcanzara? ¿a que altura se hallaba 1 segundo después del lanzamiento?
Answer:
a) [tex] y_{max} = 7.7 m [/tex]
b) y = 7.4 m
Explanation:
a) La altura máxima que alcanza la pelota se puede encontrar usando la siguiente ecuación:
[tex] y_{max} = y_{0} + v_{0y}t - \frac{1}{2}gt^{2} [/tex] (1)
En donde:
[tex]y_{0}[/tex]: es la altura inicial = 0
[tex]v_{0y}[/tex]: es la velocidad inicial en y
g: es la gravedad = 9.81 m/s²
t: es el tiempo
Primero debemos encontrar la velocidad inicial en y:
[tex] v_{fy} = v_{0y} - gt [/tex]
Sabiendo que la velocidad final en y es igual a cero (en la altura máxima), y con t = 1.25 s (la mitad del tiempo total) tenemos:
[tex] v_{0y} = gt = 9.81 m/s^{2}*1.25 s = 12.3 m/s [/tex]
Ahora, podemos encontrar la altura máxima:
[tex] y_{max} = v_{0y}t - \frac{1}{2}gt^{2} = 12.3 m/s*1.25 s - \frac{1}{2}9.81 m/s^{2}*(1.25 s)^{2} = 7.7 m [/tex]
b) Podemos encontrar la altura cuando t = 1 s con la misma ecuación (1):
[tex]y_{max} = y_{0} + v_{0y}t - \frac{1}{2}gt^{2} = 12.3 m/s*1 s - \frac{1}{2}9.81 m/s^{2}*(1 s)^{2} = 7.4 m[/tex]
Por lo tanto, la pelota se encontraba a 7.4 m luego de 1 segundo despúes del lanzamiento.
Espero que te sea de utilidad!
An object with an initial speed of 4.0 m/s accelerates uniformly at 2.0 m/s^2
in the direction of its motion for a distance of 5.0 meters. What is the final
speed of the object?
How do you measure the wavelength of wave?
Explanation:
by finding the distance between two successful crest
Answer:
the wavelength can be measured as the distance from crest to crest or from trough to trough , the wavelength of a wave can be measured as the distance from a point on a wave to the corresponding point on the next cycle of the wave.
Explanation:
Momentum is a product of mass and....?
Answer:
Momentum is a product of mass and velocity.
Explanation:
Hope this helps you
Crown me as brainliest:)
if 8000cm3 of liquid drains off an hour glass in one hour, what is the flow rate of water from the clock
Answer:
8000cm³/hr
Explanation:
Given parameters:
Volume of the liquid draining off per hour = 8000cm³
Time taken to drain off = 1hr
Unknown:
Flow rate = ?
Solution:
Flow rate is the volume of fluid that passes per unit of time.
Flow rate = [tex]\frac{volume of fluid}{time taken}[/tex]
Flow rate = [tex]\frac{8000cm^{3} }{1hr}[/tex]
Flow rate = 8000cm³/hr
which of the following best represents force?
1-a push or a pull acting on a object.
2-a push or a pull always causing acceleration.
3-a push or a pull action without an object.
4-a push or a pull always causing motion
Answer:
1 -a push or a pull acting on a object.
Explanation:
force is a push or pull acting upon an object as a result of its interaction with another object.
which change to a circuit is most likely to increase it electrical power
A: increase it's current and increase it's voltage
B: decrease it's current and increase it's voltage
C: decrease it's current and decrease it's voltage
D: increase it's current and decrease it's voltage
Answer:
A................
Explanation:
Hope this helps you
A. increase it's current and increase it's voltage
Explanation:
A 7-kg bowling ball moving at 4 m/s strikes a 1 kg bowling pin. If the ball slows to 2 m/s in 0.05 s, how much force does it exert on the pin?
Please, show your work.
Answer:
280 N
Explanation:
acceleration = v2-v1 / time taken = (2-4 )/ 0.05 = -40 m/s^2 ( neg sign indicates slowing down )
force exerted = ma = 7 kg x -40 m/s^2 = - 280 N ( neg sign means opposite direction of initial velocity )
since the 7 kg ball is slowing down, the direction of force will be opposite of the initial velocity , and it will be 280 N