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
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.
Hope I helped!
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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]
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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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
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:
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!
please help!!!!!!!!!!!!!!!!!!!!!!
Answer: I'm sure the answer is a.
Explanation: I hope that helped you.
Answer:
Precipitate
Explanation:
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
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]
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
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."
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
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 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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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
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.
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?
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:
What does a horizontal line on a position time graph indicate
A horizontal line means the object is. not changing its position it is not moving, it is at rest.
Answer:
horizontal lines on any chart is where the y axis values are equal.
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?
What is potential mechanical energy
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.
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:)
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.
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:
pls help me i need both answers pls help me this is being timed.
Answer:
it would have to be diagram C OR B
An acorn falls 10 meters in 4 seconds. What is its average velocity?
Answer:
Average velocity, V = 2.5m/s
Explanation:
Given the following data
Displacement = 10m
Time = 4secs
Average velocity can be defined as the rate of change in displacement with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, average velocity is given by the equation;
[tex]Velocity = \frac{displacement}{time}[/tex]
[tex]V = \frac{d}{t}[/tex]
Substituting into the above equation;
[tex]V = \frac{10}{4}[/tex]
Average velocity, V = 2.5m/s
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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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.
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