Answer:
this is a homework helping website I don't know If I can help you with this problwm
Two disks are rotating about the same axis. Disk A has a moment of inertia of 3.4 kg m^2 and an angular velocity of 7.2 rad/s. Disk B is rotating with an angular velocity of -9.8 rad/s. The two disks are then linked together without the aid of any external torques, so that they rotate as a single unit with an angular velocity of -2.4 rad/s. The axis of rotation for this unit is the same as that for the separate disks. What is the moment of inertia of disk B
Answer:
I = 4.4 kg*m^2
Explanation:
As no external torques are present, total angular momentum must be conserved, as follows:[tex]L_{o} = L_{f} (1)[/tex]
The initial angular momentum of the two disks rotating separately, can be written as follows:[tex]L_{o} =I_{A} * \omega_{oA} + I_{B} * \omega_{oB} (2)[/tex]
Replacing by the givens, we get:[tex]L_{o} = 3.4kg*m2 * 7.2rad/s + I_{B} * (-9.8 rad/s) (3)[/tex]
The final angular momentum Lf, as the axis of rotation remains the same, is the product of the moment of inertia of both disks rotating as one, and the common angular velocity ωf, as follows:[tex]L_{f} = (I_{A} + I_{B}) *\omega_{f} (4)[/tex]
Replacing by the givens, we get:[tex]L_{f} = (3.4 kg*m2 + I_{B} ) * (-2.4 rad/s) (5)[/tex]
From (3) and (5), we can solve for IB, as follows:IB = 4.4 kg*m2The velocity of a wave is 500 m/s . The wavelength of the wave is 3.2 m . What is the frequency of the wave ?
Answer:
f=156.25Hz
Explanation:
v=fT
500=fx3.2
500=3.2f
divide both sides by 3.2
f=156.25Hz
Help please I would appreciate it
Answer:
i think the red runner travels greater distance ie.40 m
Explanation:
although ,the blue one travels 21 m but in the backward direction .so the correct ans is "the red runner travels 40 m"
Examples of ohm law and conductor resistance :
So I need help with these things, I did 2 examples but with these 3 I have problems.
I appreciate alot if anyone can handle this
1.Calculate the resistance of a Cu 2-wire line of total length for 1 line of 500m, if it has a cross section of 6mm2.
3.Calculate the voltage drop across the resistor R = 1.2 kΩ when a current I = 125 mA flows through it
2.Calculate the current flowing through the resistor R = 47 Ω if the source has a voltage U = 24 V.
I"m attaching also Microsoft Word file.
Thanks in advance!
-Mathew
Answer:
see attached file
Explanation:
A girl rides her bike at 15 m/s for 20 s. How far does she travel in that time?
We are given:
Initial Velocity(u) = 15 m/s
Time interval(t) = 20s
Solving for the distance covered:
Since the girl keeps riding her bike at 15 m/s, her speed is constant and hence, acceleration of the bike is 0 m/s²
acceleration(a) = 0 m/s²
We know that:
s = ut + 1/2(at²) [second equation of motion]
s = (15)(20) + 1/2(0)(400) [plugging the values]
s = 150 + 0
s = 300 m
Hence, the girl covered 300 m in 20 seconds
Use the following information to answer questions 4 and 5:
A rock is launched vertically into the air at a velocity of 14.75 m/s.
4. Toby claims that the rock must come to rest before it can fall back towards the ground. Is Toby
correct?
A. Toby is correct because the rock is experiencing a negative acceleration, causing its negative
velocity to increase until the rock reaches a velocity of O m/s before becoming positive.
B. Toby is correct because the rock is experiencing a negative acceleration, causing its positive
velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
C. Toby is incorrect because the rock is experiencing a positive acceleration, causing its positive
velocity to increase in magnitude.
D. Toby is incorrect because the rock is experiencing a negative acceleration, causing its positive
velocity to increase in magnitude.
5. Calculate the time it takes for the rock to reach its maximum height.
A. 1.50 seconds
B. 2.47 seconds
C. 3.00 seconds
D. 4.94 seconds
Question 4
B. Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
Question 5
At the maximum height, velocity is 0, so:
v = v₀ - gt
0 = 14.75 - 9.8t
t = 14.75/9.8
t = 1.5 s (OPTION A)
4). In the given situation, the assertion that could be made regarding Toby would be:
B). Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
5). The time that would be taken by the rock to attain its greatest height would be:
1.5 second
4). Tobby correctly states as rock would be undergoing a -ve acceleration which leads its +ve velocity to fall by the time rock attains the velocity of 0 m/s.
Thus, option B is the correct answer.
5). Given that,
Initial velocity([tex]v_{0}[/tex]) = 14.75 m/s
As we know,
Velocity remains 0 m/s at the greatest height,
So,
Velocity(v) [tex]= v_{0} - gt[/tex]
where
[tex]0 = 14.75 - 9.8t[/tex]
⇒ [tex]t = 14.75/9.8[/tex]
∵ [tex]t = 1.5 s[/tex]
Learn more about "Velocity" here:
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An object whose specific gravity is 0.850 is placed in water. What fraction of the object is below the surface of the water?
Answer:
The fraction of the object that is below the surface of the water is ¹⁷/₂₀
Explanation:
Given;
specific gravity of the object, γ = 0.850
Specific gravity is given as;
[tex]specific \ gravity = \frac{density \ of the \ object}{density \ of \ water}\\\\0.85= \frac{density \ of the \ object}{1000 \ kg/m^3} \\\\density \ of the \ object = 850 \ kg/m^3[/tex]
Fraction of the object's weight below the surface of water is calculated as;
[tex]= \frac{850}{1000} \ \times\ 100\%\\\\= 85 \% \\\\= \frac{17}{20}[/tex]
Therefore, the fraction of the object that is below the surface of the water is ¹⁷/₂₀
The phrase "ten meters per second squared" describes the
Answer:
Acceleration
Explanation;
change in velocity over timeTherefore metre per second over second, which is meter per second squaredWho won Miami Dolphins or Las Vegas raiders
Answer:
miami dolphins.
Explanation:
......
Answer:
miami :(
Explanation:
How do the potential and kinetic energy change as the sled moves down the slope?
IF YOU DID SLED WARS WORKSHEET HELP ME PLEASE
Answer:
when a sled is moving, the kinetic energy is changing beacuse of the speed and mass. its cause the sled to move, and changes because you aren't at a constant speed. potential energy changes when you get on. because you are adding more weight causing the gravity to change.
how would you write 4.3756 in standard decimal form
How does solar energy impact the environment? Use in your own words.
two spheres A and B are projected off the edge of a 1.0 m high table with the same horizontal velocity . sphere A has a mass of 20.g and sphere B has a mass of 10.g.
If both spheres leave the edge of the table at the same instant, sphere A will land
a. at some time after sphere B.
b. at the same time as sphere B.
c. at some time before sphere B.
d. There is not enough information to decide.
__ 6. If both spheres leave the edge of the table at the same instant, sphere A hits the floor at the spot marked X. Sphere B will hit the floor
a. at some point between the edge of the table and X.
b. at some point past X.
c. at the same distance from the table as X.
d. there is not enough information to decide.
Answer:
C. and D.
C. becuase A is heavier so it will land first
Just do the attachment
Answer: your answer is B I know that's what you picked but I believe it is correct! look below...
Explanation: A solution is made when one substance called the solute "dissolves" into another substance called the solvent. Dissolving is when the solute breaks up from a larger crystal of molecules into much smaller groups or individual molecules.
In order to form a solution, the solute must be surrounded, or solvated, by the solvent. Solutes successfully dissolve into solvents when solute-solvent bonds are stronger than either solute-solute bonds or solvent-solvent bonds.
BRAINLIEST?
Use the following free body diagram to answer questions 8 and 9:
8. Calculate the net force acting on the cart.
A 0N
B. +60N
C -60N
D. +240 N
9. Calculate the cart's rate of acceleration
A +60 m/s
B. +8 m/s
C.-2m/s
D. +2 m/s
Answer:
8 is c and 9 is b it is shown though the practice as god lol
Question 8
The net force acting on the cart is:
F = 150 N - 90 N
F = 60 N
Question 9
By the Newtons second law:
F = ma
Solving for a:
a = F/m
a = 60 N / 30 kg
a = 2 m/s²
Three identical train cars, coupled together are rolling east at 2.0 m/s. A fourth car traveling east at 4.0 m/s catches up with the three and couples to make a fourcar train. A moment later the train cars hit a fifth car that was at rest on the tracks, and it couples to make a five car train. What is the speed of the five car train?
Answer:
The value is [tex]v = 2 \ m/s[/tex]
Explanation:
From the question we are told that
The velocity of the each of the three cars is [tex]u_1 = u_2 = u_3 = 2 \ m/s[/tex]
The velocity of the fourth car is [tex]u_4 = 4 \ m/s[/tex]
The initial velocity of the fifth car [tex]u_5 = 0 \ m/s[/tex]
Generally from the law of momentum conservation we have that
[tex]m_1 u_1 + m_2 u_2 + m_3 u_3 +m_4u_4 + m_5u_5 = [m_1 + m_2 + m_3 +m_4+ m_5]v[/tex]
Given that the cars are identical then their mass will be the same
i.e
[tex]m_1 =m_2 = m_3 = m_4 = m_5 = m[/tex]
=> [tex][u_1 + u_2 + u_3 +u_4 + u_5]m = 5mv[/tex]
=> [tex]2+ 2 + 2 +4 + 0 = 5v[/tex]
= > [tex]v = 2 \ m/s[/tex]
Which has a greater force: a semi-truck at rest or a moving bicycle?
Although the semi truck certainly has a larger mass, it is not in motion and therefore does not have any momentum. The bicycle however has both mass and velocity and therefore has the larger momentum of the pair.
Car 2 and Car 3 are driving down the road at the same speed. Car 1, going 15 m/s, has just passed Car 2 and is approaching Car 3 when he sees Person A standing in front of him. The driver of Car 1 quickly honks his horn as a warning, but does not brake. At the moment that Car 1 honks his horn, Person B is riding his bicycle, behind, but in the same direction as Car 1 at 7 m/s. Which person hears the highest frequency from the horn?
Answer:
Person A
Explanation:
Person A hears the highest frequency from the horn than Person B because Person A is present in front of a Car 1 while the Person B present behind the Car 1. The car horn is present at the front so the Person A will hear the highest frequency from the horn as compared to Person B which hears lower frequency from the horn. If the horn is present at the back side so Person B will hear highest frequency from the horn.
What best describes the speed of light waves in solids, liquids, and gases?
The speed is fastest in solids.
The speed is fastest in liquids.
The speed is fastest in gases.
The speed is the same in all matter.
Answer: It’s fastest in gases. Letter C !
Explanation:
Answer:
its c
Explanation:
Calculate the change in entropy of 0.020 kg of ice when it melts at 0.0°C. The heat of fusion of ice is 3.36 x 10'J/kg.
Answer:
S = 2461.53 [kJ]
Explanation:
The change in entropy in a process such as melting can be calculated by means of the following expression.
[tex]S=\frac{H*m}{T}[/tex]
where:
S = entropy [kJ]
H = fusion heat = 3.36*10¹ [J/kg]
m = mass = 0.02 [kg]
T = temperature in kelvin = 273 [K]
[tex]S = \frac{0.02*3.36*10^{1} }{(273+0)}\\S = 2461.53 [kJ][/tex]
a passenger of mass m on a Ferris wheel moves in a vertical circle of radius r with constant speed v assuming that the seat remains upright during the motion which is true about the force the seat exerts on the passenger at the top of the circle
the upward force is equal in magnitude to the passenger's weight
the upward force is greater in magnitude than the passenger's weight
the upward force is smaller in magnitude than the passenger's weight
the upward force is zero
Answer:
the upward force is equal to the passenger weight
The answer that is the truth about the force that the seat exerts on the passenger is the upward force is equal in magnitude to the passenger's weight.
Why the upward force is equal in magnitude to weight
The acting forces on the body has been said to be vertical. This implies that the upward force and the downward force of gravity are the same.
Using the second law of Isaac Newton, the downward direction of the forces would be ascertained.
Read more on force and magnitude here:
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1. A 3.8 kg scooter moves with a constant acceleration of 2.5 m/s”. Determine the net
applied force responsible for the acceleration.
Answer:
9.5 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3.8 × 2.5
We have the final answer as
9.5 NHope this helps you
A 1kg dictionary is resting on a table that is 1.5m high. How much potential energy
does it have?
Answer:
Potential energy = 14.7 Joules.
Explanation:
Given the following data;
Mass, m = 1kg
Height, h = 1.5m
We know that acceleration due to gravity is equal to 9.8m/s²
Potential energy can be defined as an energy possessed by an object or body due to its position.
Mathematically, potential energy is given by the formula;
[tex] P.E = mgh[/tex]
Where, P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
[tex] P.E = mgh[/tex]
Substituting into the equation, we have;
[tex] P.E = 1*9.8*1.5[/tex]
P.E = 14.7 Joules.
2. A car accelerates at a rate of 1.4 m/s. Find the mass of the car if a 2250 N net force is
required to produce this acceleration.
Answer:
1607.14 kgExplanation:
The mass of the car can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{2250}{1.4} \\ = 1607.14285...[/tex]
We have the final answer as
1607.14 kgHope this helps you
Use the image below to answer the question.
What does the arrow 'B' represent?
Question 7 options:
wavelength
refraction
frequency
compression
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
B. The bag increases the amount of time the force acts on the person and reduces the change in momentum.
C. The bag reduces the impulse to the person.
D. The bag provides the necessary force to stop the person.
E. The bag decreases the amount of time during which the momentum is changing and reduces the average force on the person.
Answer:
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
ANSWER: A
Answer:
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
During stunts, people usually put an-air filled bag on the ground for safe landing and to prevent injuries.
Momentum is calculated by m* v where m is for mass and v is for velocity.
Force is directly proportional to momentum
F∝M
The bag in this scenario helps to increases the amount of time the force acts on the person. This implication means that there is a reduction in the change of momentum. Since Force and momentum have a directly proportional relationship then the Force taken to hit the floor is greatly reduced.
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If two ___ forces are applied to an object in opposite directions, the object does not move, or moves at a ___ , this means the forces are ___. If to ___ forces are applied to an object in opposite directions, the object does move, this means the forces are ___.
Answer:
Equal and opposite
Constant speed
Balanced
Unequal and non-opposite
Unbalanced
Explanation:
Balanced forces can be defined as forces which are equal in size but opposite in direction.
Now, these forces do not cause a change in motion because when they act on an object at rest, such an object will not move. For example, when attempt to push against a wall, the wall will push back with an equal but opposite force and neither you nor the wall will move.
While unbalanced forces are those that cause a change in the motion of an object.
Thus, these forces are said not to be equal and opposite.
The voltage between two points in a circuit is 3.6 V. If the resistance between
the points is 75 , what is the current, according to Ohm's law?
A. 76.6 A
B. 0.048 A
C. 20.8 A
D. 270 A
Correct answer is B!
Considering the Ohm's law, the correct answer is option B. the current is 0.048 A.
Definition of currentThe flow of electricity through an object, such as a wire, is known as current (I). Its unit of measure is amps (A). So the current is a measure of the speed at which the charge passes a given reference point in a specified direction.
Definition of voltageThe driving force (electrical pressure) behind the flow of a current is known as voltage and is measured in volts (V) (voltage can also be referred to as the potential difference or electromotive force). That is, voltage is a measure of the work required to move a charge from one point to another.
Definition of resistanceResistance (R) is the difficulty that a circuit opposes to the flow of a current and it is measured in ohms (Ω).
Ohm's lawOhm's law establishes the relationship between current, voltage, and resistance in an electrical circuit.
This law establishes that the intensity of the current that passes through a circuit is directly proportional to the voltage of the same and inversely proportional to the resistance that it presents.
Mathematically, Ohm's law is expressed as:
[tex]I=\frac{V}{R}[/tex]
Where I is the current measured in amps (A), V the voltage measured in volts (V); and R the resistance that is measured in ohms (Ω).
This caseIn this case, you know that the voltage between two points in a circuit is 3.6 V and the resistance between the points is 75 Ω.
Replacing in the Ohm's Law:
[tex]I=\frac{3.6 volts}{75 ohm}[/tex]
Solving:
I= 0.048 amps
Finally, the correct answer is option B. the current is 0.048 A.
Learn more about Ohm's law:
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A car starting at rest accelerates to a speed of 6miles/hr in 5 sec what is the average acceleration
Answer:
1.2 mi/hr/sec
Explanation:
a = Vf - Vi / t (formula)
-----------------------------------
6mi/hr - 0 mi/hr 6 mi/hr
a = ____________ = _______ = 1.2 mi/hr/sec
5 sec 5 sec
how many minutes in 1 hour
Answer:
60
Explanation:
Every 60 minutes is an hour
Answer:
60; minute in 1 HR is the answer