(a) The series resistor that should be used to reduce the current to 2.0 A for low-speed operation is 3.5 ohms.
(b) The power rating the resistor should have is 17.5 W.
Given information: The current in the motor is 5.0 A when it is connected directly across a 12 V battery.
In series combination, the total resistance is given as:
RT = R1 + R2
Where, RT = Total resistance
R1 = Resistor resistance
R2 = Resistance of motor
In this problem, the current through the motor needs to be reduced to 2.0 A using a series resistor. Thus the series resistance required can be calculated as:
5.0 A - 2.0 A = 3.0 A
The voltage across the resistor is equal to the supply voltage minus the voltage across the motor, which is:
VR = VB - Vm
VR = 12 V - Vm
The voltage across the motor can be determined using Ohm's law:
Vm = Im × Rm
Where, Im = Current through the motor
Rm = Resistance of motor
Therefore,
VR = 12 V - 5.0 A × Rm
The series resistance is:
R1 = VR / I1
Where, I1 = Current required (2.0 A)
Thus, R1 = VR / I1 = (12 V - 5.0 A × Rm) / 2.0 A
3.5 ohms is the series resistor that should be used to reduce the current to 2.0 A for low-speed operation.
For the power rating of the resistor, it can be calculated using:
P = V^2 / R
Where, V = Voltage across the resistor (12 V - 5.0 A × Rm)
R = Resistor resistance
Thus, P = (12 V - 5.0 A × Rm)^2 / 3.5 ohms = 17.5 W
Therefore, the power rating that the resistor should have is 17.5 W.
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find the displacement shown in the graph. Give your answer to 3 significant figures.
What is the acceleration between 0 and 3 seconds?
which is heavier , 1kg of steel or i kg of cork
Answer:
Same weight so neither is heavier
Since their masses are equal, their weights are equal whenever they're both on the same planet.
A driver traveling at 100\,\dfrac{\text{km}}{\text{h}}100 h km 100, start fraction, start text, k, m, end text, divided by, start text, h, end text, end fraction notices the speed limit changes to 50\,\dfrac{\text{km}}{\text{h}}50 h km 50, start fraction, start text, k, m, end text, divided by, start text, h, end text, end fraction. The driver takes 0.9\,\text{s}0.9s0, point, 9, start text, s, end text to slow down to 50\,\dfrac{\text{km}}{\text{h}}50 h km 50, start fraction, start text, k, m, end text, divided by, start text, h, end text, end fraction with constant acceleration. We want to know how many meters the driver travels while slowing down.
Answer:
67.5
Explanation:
d = (Vo+ v/2)t
d = (150/2)(0.9)
d = 67.5
The effectiveness of biofeedback has been a subject of controversy because biofeedback __________.
A.
has no reported side effects
B.
cannot be effectively tested
C.
has no reported negative effects
D.
requires uncomfortable electrodes
please help
Answer:
B
Explanation:
cannot be effectively tested
The effectiveness of biofeedback has been a subject of controversy because biofeedback cannot be effectively tested.
What is biofeedback therapy?
You can learn to control certain of your body's functions, like your heart rate, using a technique called biofeedback.You are connected to electrical sensors during biofeedback, which enables you to learn more about your body.An alternative medical strategy called biofeedback instructs patients on how to influence how their bodies work.Your physical and emotional health may be improved by this mind-body therapy.An expert monitors your body's processes using devices and monitoring equipment during a biofeedback session. With the aid of visual or aural feedback, people can learn to recognize the bodily manifestations of stress and anxiety, such as elevated heart rate, body temperature, and tense muscles.Sensors linked to your body are used in biofeedback therapy to track important bodily processes.You are supposed to learn more about how your body functions with the aid of biofeedback.You might be able to address health issues and gain better control over some bodily systems with the assistance of this knowledge.Biofeedback is generally safe, but it might not be appropriate for everyone. Biofeedback devices might not work properly on people with certain medical conditions, such as heart rhythm problems or certain skin conditionsTo learn more about biofeedback refer
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PLEASE ASAP
Giving a brainlist
Answer:
Stationary
Explanation:
This is a position-time graph, meaning it shows an object's position over time. If the line is flat, it means that the object has not changed position during that time period, therefore it is stationary between the points g and h.
Hope this helped!
why does the fast working machine posses more power?
Answer:
A chemical reaction increase in speed with the increase of temperature.. so.. fast working machine posses more power
What is the white part of each water molecule and what are the red parts of the water molecules?
Answer:
hydrogen are the white parts and the red parts are oxygen
one part Hydrogen, two parts oxygen (H2O)
Hydrogen atom is the white part and the red parts are oxygen atoms of water molecule - one part Hydrogen, two parts oxygen (H₂O) in water molecule.
What is the water (H₂O) molecule?Each H₂O molecule is V-shaped and is made up of one oxygen atom and two hydrogen atoms. Hydrogen bonds allow adjacent H₂O molecules to temporarily connect with one another (depicted as blue and white ovals).
Individual H₂O molecules are held together by powerful bonds between the hydrogen (white) and oxygen (red) atoms. When two atoms—in this case, oxygen and hydrogen—share electrons, a covalent link is created. Each end of the V-shaped H₂O molecule adopts a slightly different charge because oxygen and hydrogen draw the shared electrons from each other in different ways. In contrast to the opposite, hydrogen-containing end of the molecule, which is somewhat positive, the region around the oxygen is relatively negative.
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Mali loves to make herself dizay. She spins around in place 7 times before falling down right where she
was stand. Find har distance and displacement.
If she is spinning on the spot she is not travelling anywhere so her distance and displacement are zero.
What is Distance and Displacement?Physics words like distance and displacement are crucial to understand right because they are frequently misunderstood.
Displacement, a vector quantity, is the shortest path in a straight line between the starting position and the final position. Distance is a scalar quantity, measuring the total distance traveled by an object.
A vector quantity is different from a scalar quantity in that a vector quantity has directional information while a scalar quantity is just a set of integers. A variable with "half-arrows" above it is a vector quantity.
Therefore, If she is spinning on the spot she is not travelling anywhere so her distance and displacement are zero.
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What is the relationship between a revolution and an orbit?
You need to estimate the floor area of your unusual oval shaped living room from memory you remember that it is longer than wider and is about 6m long . So you take it to b rectangular with a witdth of 0.5 m and multiply width by length to get an estimate of 3m why was your estimate not done correctly
Answer:
Our estimate not done correctly because the width was unrealistic.
Explanation:
Given that,
Length = 6 m
Width = 0.5 m
We need to calculate the area of rectangular floor
Using formula of area
[tex]A=l\times w[/tex]
Where, l = length
w= width
Put the value into the formula
[tex]A=6\times0.5[/tex]
[tex]A=3\ m^2[/tex]
We need to find why this estimate not done correct
Using given data
We can say that,
We assume width was unrealistic.
The length of room is 6 m.
We know that,
[tex]1\ m=3.28\ feet[/tex]
So, the length would be 20 feet.
The width of room is 0.5 m.
The width of room would be 1.64 feet.
So, the area will be
[tex]A=20\times1.64[/tex]
[tex]A=32.8\ feet^2[/tex]
Hence, Our estimate not done correctly because the width was unrealistic.
DESPERATE WIL GIVE BRAINLIST
Which type of rock will be formed if sedimentary rock becomes molten and then hardens?
A. metamorphic
B. igneous
C. clastic
D. foliated
Answer:
Igneous
Explanation:
Which type of atom has the same number of protons and electrons
A cheetah runs at 93km/he to the east. This describes the cheetah’s
A.) Displacement
B.) Instantaneous Speed
C.) Average Speed
D.) Average Velocity
A celestial body orbits the Sun. It consists of rock and ice. As it passes close to the Sun, the body forms a long tail of dust. Which body best matches this description?
Answer: A Comet
Explanation: A comet is a small icy body that when passing close to the sun, heats up in releases gases, producing invisible tail.
what does it mean by the fact that the acceleration of a car is 5m/s square??
Answer:
An acceleration of 5m/s^2 means that the velocity of a body is increasing by 5m/s per second in a certain direction
Explanation:
What is the kinetic energy of a 0.50 kg ball traveling at a speed of 120 m/s?
Answer:
The answer is 3600 JExplanation:
The kinetic energy (KE) of an object given it's mass and velocity can be found by using the formula
[tex]KE = \frac{1}{2} m {v}^{2} \\ [/tex]
where
m is the mass of the object
v is the velocity
From the question
m = 0.5 kg
v = 120 m/s
So we have
[tex]KE = \frac{1}{2} \times 0.5 \times {120}^{2} \\ = \frac{1}{4} \times 14400[/tex]
We have the final answer as
3600 JHope this helps you
2. One cubic centimeter (cm3) is the same volume as one...
1. Which mathematical representation correctly identifies impulse?
A. implulse= force/time
B. impulse= force * time
C. impulse= acceleration * time
D. impulse= velocity/time
2. In a closed system, a ball with a mass of 3 kg and a momentum of 24 kg·m/s collides into a ball with a mass of 1 kg that is originally at rest. Which statement describes the momentum of the balls and the total momentum?
A. The momentum of each ball changes, and the total momentum stays the same.
B. The momentum of each ball changes, and the total momentum changes.
C. The momentum of each ball stays the same, and the total momentum stays the same.
D. The momentum of each ball stays the same, and the total momentum changes.
3. In a closed system, three objects have the following momentums: 110 kg⋅m/s, −65 kg⋅m/s, and −100 kg⋅m/s. The objects collide and move together. What is the total momentum after the collision?
A. -55 kg*m/s
B. -275 kg*m/s
C. 275 kg*m/s
D. 55 kg*m/s
4. In a closed system, an object with a mass of 1.5 kg collides with a second object. The two objects then move together at a velocity of 50 m/s. The total momentum of the system is 250 kg⋅m/s. What is the mass of the second object?
A. 3.0 kg
B. 3.5 kg
C. 5.0 kg
D. 1.5 kg
5. A cue stick has a mass of 0.5 kg. The cue stick hits a ball with a mass of 0.2 kg at a velocity of 2.5 m/s. What is the velocity of the ball after it is hit?
A. 2.5 m/s
B. 8.3 m/s
C. 6.3 m/s
D. 3.6 m/s
Answer:
1. B. Impulse = Force × Time
2. A. The momentum of each ball changes, and the total momentum stays the same
3. -55 kg·m/s
4. B. 3.5 kg
5. C. 6.3 m/s
Explanation:
1. The impulse is the momentum change of an object due to a force applied for a given period
2. Given that the objects collide, and the force of the 3 kg mass moving with 24 kg·m/s acts on the 1 kg mass while the total momentum is conserved;
The stationary ball of mass 1 kg begins to moves at certain velocity after collision and therefore changes momentum, while the velocity of the ball of mass 3.0 kg reduces and the total combined momentum of the two balls in the closed system remains the same
3. By the principle of conservation of linear momentum, we have;
The sum of the momentum before the collision = The sum of the momentum after collision
Given that the objects move together after the collision, the total momentum is therefore;
Total momentum = 110 kg·m/s + -65 kg·m/s + -100 kg·m/s = 110 kg·m/s - 65 kg·m/s - 100 kg·m/s = -55kg·m/s
4. Given that the final velocity of the two objects (m₁ + m₂) combined = 50 m/s
Where;
m₁ = The mass of the first object
m₂ = The mass of the second object
The total momentum of the system = 250 kg·m/s
From momentum = Mass × Velocity, we have;
Mass = Momentum/Velocity = 250 kg·m/s/(50 m/s) = 5.0 kg
The mass (m₁ + m₂) = 5.0 kg
Given that m₁ = 1.5 kg, we have;
m₂ = 5.0 kg - m₁ = 5.0 kg - 1.5 kg = 3.5 kg
The mass of the second object = 3.5 kg
5. The mass of the cue stick = 0.5 kg
The velocity of the cue stick = 2.5 m/s
The mass of the ball = 0.2 kg
The initial velocity of the ball = 0 m/s
Given that total initial momentum = Total final momentum, we have;
0.5 kg × 2.5 m/s + 0.2 kg × 0 = 0.2 kg × v + 0.5 kg × 0
0.5 kg × 2.5 m/s = 0.2 kg × v
v = (0.5 kg × 2.5 m/s)/(0.2 kg) = 6.25 m/s ≈ 6.3 m/s
A car starts from rest and accelerates uniformly at 6.6 m/s2 for 10.s. How far does the car travel?
Explanation:
s = ut + 1/2at²
= 0(10) + 1/2×6.6×(10)²
= 3.3 × 100
= 330 m
During WWI, the Germans had a gun called Big Bertha that was used to shell Paris. The shell had an initial speed of 1700 m/s, and was shot with an inclination of 55 degrees. In order to hit the target, adjustments were made for air resistance. Ignoring frictional effects, calculate the following:
a.The Horizontal and Vertical Velocities
b.How far away did the shell hit?
c. How long was the shell in the air?
Answer:
[tex]975.1\ \text{m/s}[/tex] and [tex]1392.56\ \text{m/s}[/tex]
[tex]276830.96\ \text{m}[/tex]
284 seconds
Explanation:
(a) [tex]u=\text{Initial velocity}=1700\ \text{m/s}[/tex]
[tex]\theta[/tex] = Angle of inclination = [tex]55^{\circ}[/tex]
Horizontal velocity is given by
[tex]u_x=u\cos\theta\\\Rightarrow u_x=1700\times \cos55^{\circ}\\\Rightarrow u_x=975.1\ \text{m/s}[/tex]
Vertical velocity is given by
[tex]u_y=u\sin\theta\\\Rightarrow u_x=1700\times \sin55^{\circ}\\\Rightarrow u_x=1392.56\ \text{m/s}[/tex]
The horizontal and vertical velocities are [tex]975.1\ \text{m/s}[/tex] and [tex]1392.56\ \text{m/s}[/tex] respectively.
(b) Range of projectile is given by
[tex]R=\dfrac{u^2\sin2\theta}{g}\\\Rightarrow R=\dfrac{1700^2\sin(2\times 55^{\circ})}{9.81}\\\Rightarrow R=276830.96\ \text{m}[/tex]
The shell hit the ground [tex]276830.96\ \text{m}[/tex] from the launch position.
(c) Time of flight is given by
[tex]t=\dfrac{2u\sin\theta}{g}\\\Rightarrow t=\dfrac{2\times 1700\times \sin55^{\circ}}{9.81}\\\Rightarrow t=284\ \text{s}[/tex]
The shell was in the air for 284 seconds.
A substance with no definite volume and no definite shape is classified as a —
When would an objects average speed and average velocity be different?
Answer:
the motion of an object is along a straight line and in the same direction, the magnitude of displacement is equal to the total path length. In that case, the magnitude of the average velocity is equal to the average speed.
Why is pascal called a derived unit
Which theory do scientists believe MOST LIKELY explains the creation of the universe?
A) Big Bang Theory
B) Radiation Theory
C) Red Shift Theory
Eliminate
D) Butterfly Effect Theory
Hundreds of years ago, it was believed by many that our solar system was Geocentric. This means that Earth is at the center of the solar system, with the Sun and other planets orbit around it. Today, the solar system is now thought to be Heliocentric.
What does this mean?
A) The Sun and other planets orbit Earth.
B) Earth and all the other planets orbit the Sun.
C) The other planets orbit Earth, and Earth orbits the Sun.
D) The Sun orbits Earth and the other planets orbit the Sun.
Answer:
1st one is: A
2nd one is: B
The use of fossil fuels is more than other fuels at present.why...
Calculate the increase in the gravitational potential
energy store of a car lifted 2.5m off the floor. The
mass of the car is 950 kg.
Gravitational field strength is 9.8 N/kg.
a car goes from 4.47 m/s to 17.9 m/s in 3 seconds. calculate the acceleration of the car
Answer:
4.48 m/s²
Explanation:
Acceleration is change in velocity over time.
a = Δv / Δt
a = (17.9 m/s − 4.47 m/s) / 3 s
a = 4.48 m/s²
Answer:
[tex]\boxed {\tt a \approx4.48 \ m/s^2}[/tex]
Explanation:
Acceleration can be found by dividing the change in velocity over the time.
[tex]a=\frac{\Delta v}{t}[/tex]
The change in velocity can be found by subtracting the final velocity by the initial velocity.
[tex]\Delta v= final \ velocity - initial \ velocity[/tex]
The final velocity is 17.9 meters per second.
The initial velocity is 4.47 meters per second.
[tex]\Delta v=17.9 \ m/s-4.47 \ m/s[/tex]
[tex]\Delta v=13.43 \ m/s[/tex]
The change in velocity is 13.43 meters per second and the time is 3 seconds.
[tex]a=\frac{13.43 \ m/s}{3 \ s}[/tex]
Divide.
[tex]a=4.47666667 \ m/s^2[/tex]
[tex]a \approx4.48 \ m/s^2[/tex]
The acceleration is about 4.48 meters per seconds squared.
Spaceship 1 and Spaceship 2 have equal masses of 300 kg. Spaceship 1 has
a speed of 0 m/s, and Spaceship 2 has a speed of 6 m/s. What is the
magnitude of their combinied momentum?
A. 1,200 kg-m/s
B. 18 kg-m/s
C. 1,800 kg-m/s
D. 3,600 kg-m/s
PLEASE HELP FAST
Answer:
C, 1800kg/s
Explanation:
You multiply the mass (300) by the change in the two velocities (6-0=0). Then you’ll get 1800.. sorry if I’m wrong
A baseball dropped from the roof of a tall building takes 4.1 seconds to hit the ground. How tall is the building?
Answer:
It is about 78
Carmen is helping load furniture and boxes onto a moving truck. She picks up boxes of her things, places them on a cart, and pushes the cart to the moving van. Which term best describes the type of force Carmen uses?
A. contact
B. friction
C. gravity
D. noncontact
Answer:
B because of the friction from the wheels
