Answer:
22/0.50=44
Explanation:
average speed= distance / time
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."
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 8,000 kg amazon truck carrying a 3000 kg package is moving at 20 m/s along a level road as shown to the left. The driver applies the brakes to slow down. The truck travels 50 meters while applying the brakes for 3.0 seconds. The package does not slide on the back of the truck. a) Calculate the rate of acceleration b) Calculate the minimum coefficient of friction between packages and the truck
Answer:
(a) -6.67 [tex]m/s^2[/tex]
(b) 0.68
Explanation:
Given that the mass of the truck, [tex]m_1=8000[/tex] kg.
Mass of the package, [tex]m_2=3000[/tex] kg.
As the package does not slide, so the acceleration of both, truck as well as the package, is the same.
Let [tex]a\;\; m/s^2[/tex] is the acceleration of the combined mass, m.
[tex]m=m_1+m_2= 8000+3000=11000[/tex] kg.
The initial velocity of the combined mass, u= 20 m/s.
Time required to stop, t=3 seconds.
Final velocity, v=0.
Displacement traveled, s=50 m.
(a) As [tex]a=\frac {v-u}{t}[/tex]
[tex]\Rightarrow a=\frac{0-20}{3}=-\frac{20}{3} =6.67 m/s^2[/tex]
Hence the acceleration of the truck is [tex]-6.67 m/s^2.[/tex]
(b) Now, [tex]a=-6.67 m/s^2[/tex] is the acceleration of the package, this acceleration is due the frictional force, f.
Due to inertia, on application of break, the package have tendency to slide to left (in the direction of velocity). But the package does not slides, this is only due to the frictional force, f, which acts in the right direction ( opposite to the direction of velocity).
So, the magnitude of frictional force required on [tex]m_2[/tex] to avoid slide is
[tex]f=|m_2a|=\frac{20}{3}m_2\times(i)[/tex]
Now, let \mu be the minimum coefficient of the friction, so
The force due to friction, [tex]f_r= \mu N[/tex],
where [tex]\mu N[/tex] is the normal reaction.
[tex]N=m_2g[/tex], where g is the acceleration due to gravity.
So, [tex]f_r=\mu m_2g\cdots(ii)[/tex]
To avoid slide, [tex]f_r\geq f[/tex]
[tex]\Rightarrow \mu m_2g\geq\frac{20}{3}m_2[/tex] [from (i)and (ii)]
[tex]\Rightarrow \mu\geq \frac{20}{3\times 9.81}[/tex] [tex][ as \;g=9.81 m/s^2][/tex]
[tex]\Rightarrow \mu \geq 0.68[/tex]
Hence, the minimum value of coefficient of friction between packages and the truck os 0.68.
A skater of mass 60 kg has an initial velocity of 12 m/s. He slides on ice where the frictional force is 36 N. How far will the skater slide before he stops?
Answer:
d = 120 [m]
Explanation:
In order to solve this problem, we must use the theorem of work and energy conservation. Where the energy in the final state (when the skater stops) is equal to the sum of the mechanical energy in the initial state plus the work done on the skater in the initial state.
The mechanical energy is equal to the sum of the potential energy plus the kinetic energy. As the track is horizontal there is no unevenness, in this way, there is no potential energy.
E₁ + W₁₋₂ = E₂
where:
E₁ = mechanical energy in the initial state [J] (units of Joules)
W₁₋₂ = work done between the states 1 and 2 [J]
E₂ = mechanical energy in the final state = 0
E₁ = Ek = kinetic energy [J]
E₁ = 0.5*m*v²
where:
m = mass = 60 [kg]
v = initial velocity = 12 [m/s]
Now, the work done is given by the product of the friction force by the distance. In this case, the work is negative because the friction force is acting in opposite direction to the movement of the skater.
W₁₋₂ = -f*d
where:
f = friction force = 36 [N]
d = distance [m]
Now we have:
0.5*m*v² - (f*d) = 0
0.5*60*(12)² - (36*d) = 0
4320 = 36*d
d = 120 [m]
Describe Kinetic Energy.
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:
this is also for a Digital Electronics class
Answer:
Rt = 908.25 [ohm]
Explanation:
In order to solve this problem, we must remember that the resistors connected in series are added up arithmetically.
In this case, R2 and R3 are in series therefore.
R₂₃ = 200 + 470
R₂₃ = 670 [ohm]
Now this new resistor (R₂₃) is connected in parallel with the resistor R4. therefore we must use the following arithmetic expression, to add resistances in parallel.
[tex]\frac{1}{R_{4-23} }= \frac{1}{R_{4}}+\frac{1}{R_{23} } \\\frac{1}{R_{4-23} }=\frac{1}{1800}+\frac{1}{670} \\R_{4-23}=488.25[ohm][/tex]
In this way R₁, R₅ and R₄₋₂₃ are connected in series.
Rt = R₁ + R₅ + R₄₋₂₃
Rt = 150 + 270 + 488.25
Rt = 908.25 [ohm]
Attachment Lab:Conservation of Linear Momentum
Answer:
This is what I got the teacher hasn’t graded it yet so sorry if it’s not right
Explanation:
pls help me i need both answers pls help me this is being timed.
Answer:
it would have to be diagram C OR B
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.
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!
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
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
Select the correct answer
All of the following will help you safely cool foods EXCEPT:
A After a meal put leftovers in a deep container so the food cools down more slowly.
B Put cold foods away immediately after purchasing.
c.
Nestle a bowl of cold food in a slightly larger bowl of ice during a picnic.
D. Transfer cold foods directly from the refrigerator to the cooler when going out.
If someone knows this answer please help me
Answer:
I may be a little late, but it's A i got it right on the exam
Explanation:
All of the following will help you safely cool foods except after a meal put leftovers in a deep container so the food cools down more slowly, therefore the correct answer is option A.
What is thermal energy?
It can be defined as the form of the energy in which heat is transferred from one body to another body due to their molecular movements, thermal energy is also known as heat energy.
The option that will help you safely cool foods is by putting cold foods away immediately after purchasing, Nestle a bowl of cold food in a slightly larger bowl of ice during a picnic, and Transferring cold foods directly from the refrigerator to the cooler when going out.
The right response is A, option a since all of the options will help you safely cool meals, with the exception of putting leftovers in a deep container after a meal to allow them to cool more slowly.
To learn more about thermal energy here, refer to the link given below ;
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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
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
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 .
please help!!!!!!!!!!!!!!!!!!!!!!
Answer: I'm sure the answer is a.
Explanation: I hope that helped you.
Answer:
Precipitate
Explanation:
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 student tries to measure the period of a pendulum that is already swinging
left and right. At the moment when the pendulum is fully to the left, she
counts 'One' and starts a stopwatch. She counts successive swings each time
that the pendulum returns to the left. When she counts ‘Ten' she stops the
stopwatch, and sees that it reads 12.0 s.
a. What was her mistake?
______________________________________________________________
b. What is the period of swing of this pendulum?
______________________________________________________________
c. In this particular experiment, explain the likely effect of her reaction time
on her answer.
Answer:
a. The student's mistake was that the student did not swing the pendulum and start the watch at the same time.
b. 1.2 s per swing.
c. The likely effect of her reaction time is that they will should subtract two seconds off the time.
Explanation:
The pupil made the error of not simultaneously starting the watch and swinging the pendulum.
What is pendulum?Pendulum is defined as a body that is suspended from a fixed point and moves back and forth while being pulled by gravity. The pendulum is used to gauge the gravitational pull because the force of gravity causes it to swing back toward its average position. A pendulum's time period can be used to tell the time because it is constant.
The swing of the pendulum is 1.2 sec. per swing. They should take two seconds off the timing due to her presumably slow reaction time. A pendulum's total time should be divided by the quantity of oscillations in order to determine its time period. When compared to a pendulum with a shorter string, the one back and forth cycle of a longer-stringed pendulum requires more time to complete.
Thus, the pupil made the error of not simultaneously starting the watch and swinging the pendulum.
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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:)
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 space rover weighs less on Mars than it does on Earth. Which statement
explains this difference?
A. The rover is farther from Earth,
B. The rover has less mass on Mars.
C. The mass of Mars is less than the mass of Earth.
D. The gravitational constant is smaller on Mars than on Earth.
Answer:
C.) the mass of mars is less than the mass of earth.
Explanation:
The more mass of the planet, the stronger the gravitational pull is. The rover will seem lighter on mars because there is less gravity pulling it onto the planet.
The mass of mars is less than the mass of earth.
What is Earth?
The more mass of the planet, the stronger the gravitational pull is. The rover will seem lighter on mars because there is less gravity pulling it onto the planet.
Earth, the third planet from the Sun, is the planet where all known life is found. Although the Solar System contains enormous amounts of water, only Earth is home to liquid surface water.
The ocean covers roughly 70.8% of Earth's surface, dwarfing the polar ice, lakes, and rivers. Earth's surface is made up of continents and islands for the remaining 29.2% of its total area.
Therefore, The mass of mars is less than the mass of earth.
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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 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?
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
Learn more on angle of refraction here: https://brainly.com/question/15838784
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:
When a toy car is moving across a flat surface, what forces are acting on it (gravity, tension, spring, friction,air,normal,applied)?
Answer:
I believe gravity is acting on it
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:
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)