Answer:
B. commutator
Explanation:
The DC motor has a commutator, to keep the rotor rotating. The rotor of the DC motor usually stop spinning once it aligns with the magnetic field. However, the commutator would reverse the current through the stator and in this process reverse the magnetic field. This ensures continuous spinning of the rotor.
Therefore, the correct option is "B. commutator."
A girl hits a baseball with a bat. When the bat strikes the ball, what is the
reaction force?
A. Earth's gravity pulls the ball down.
B. The ball accelerates upward.
C. The bat pushes against the girl's hands.
D. The ball pushes against the bat.
When the bat strikes the ball, the ball pushes against the bat due to reaction force, The correct option is D.
What is reaction force?It is a type of force that acts in the opposite direction of the applied force, for example when one applies active force towards the stationery wall, the wall exerts a reactive force in the opposite direction.
Therefore when a girl hits a baseball with a bat, the baseball applies an active force on the ball in which as a result of reactive force the ball pushes against the bat.
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Answer:the ball pushes against the bat
Explanation:because I got it right
How long does it take an airplane to fly 5000 miles if it maintains a speed of 240 miles per hour
Please help!!! The radius of a circle is 5.5 cm, the circumference in meters is 34.56, the area in square meters is 95.03. What is the area under the curve at the right?
Answer:
47.515 cm²
In meter square= 4.7515 *10^-3 m²
Explanation:
The radius of a circle = 5.5 cm
In meter= 5.5*0.01
= 0.055 m
the circumference= 34.56 cm
in meters = 34.56 cm*0.01
= 0.3456 meters
the area= 95.03 cm²
in square meters =95.03*(0.01)²
in square meters= 9.503*10^-3 m²
. area under the curve at the right
= Area of semi circle
= Area of circle/2
= 95.03 /2
= 47.515 cm²
In meter square= 4.7515 *10^-3 m²
A total of 233 electrons pass a point in a circuit in 45 minutes. What is the current?
.1 nano ampere
Explanation:
I= Q flow/ t in secs
I= 233/2700
I= 0.0862e/sec
I= 0.0862/6.25 * 10^8 ( ampere conversion)
I= 0.1 nano ampere .
Runner A is initially 5.3 km west of a flag-
pole and is running with a constant velocity
of 8.8 km/h due east. Runner B is initially 5.0
km east of the flagpole and is running with a
constant velocity of 7.7 km/h due west.
How far are the runners from the flagpole
when their paths cross?
Answer in units of km.
the speed of a rollar coaster could be measured in
Answer:
pe=mgh
Explanation:
hope this helped
The volume of air is 53.28 m 3 . Convert it into scientific notation. 5.328×101 m3 532.8×101 m3 0.5328×103 m3 Both A and C
Explanation:
It is given that, the volume of air is 53.28 m³. We need to convert it into scientific notation.
Any number in scientific notation can be given by :
[tex]N=a\times 10^b[/tex]
a is real no and b is any integer
We have, V = 53.28 m³
To write it into scientific notation, shift decimal before 3 such that,
[tex]V=\dfrac{5328}{100}[/tex]
No multiply and divide by 10. So,
[tex]V=\dfrac{5328}{100}\times \dfrac{10}{10}\\\\V=\dfrac{5328}{1000}\times 10\\\\V=5.328\times 10^1\ m^3[/tex]
So, the correct option is (a).
What might be an indication that you watch too much TV?
My answer is addiction... It's addiction when it's the first thing you turn on in the morning and in the night when you sleep late when watching the TV.
The answer is A)0.20 but can someone explain how to solve it plsss?!!
Explanation:
The velocity of the wave is:
v = (9.0π rad/s) / (0.1π / cm)
v = 90 cm/s
v = 0.9 m/s
Velocity of a standing wave on a stretched string is:
v = √(T / (m/L))
0.9 m/s = √(0.081 N / (M / 2.0 m))
0.81 m²/s² = 0.081 N / (M / 2.0 m)
M / 2.0 m = 0.1 kg/m
M = 0.2 kg
_______ is a vector quantity; ________ is a scalar quantity.
Question 4 options:
speed...displacement
displacement...velocity
mass...velocity
velocity...distance
Answer: Velocity...Distance
Explanation: Velocity is a vector quantity as it has both magnitude and direction
Distance is a scalar quantity as it has only magnitude and no direction
hope this helped...
what is optical fibre
Answer:
Optical Fiber is a wired communication medium. It is made using one or many thin strands of glass or plastic.
Explanation:
Fiber optics is used in communications, medicine, optical inspection, lighting and in the making of sensors.
What are some of the payoffs
companies receive when offering child care
benefits to employees?
Answer:
Some of the payoffs companies receive when offering child care benefits to employees;
1) Employees are proud to tell others they work for such establishments which make the establishment attractive to talents
2) Reduced attrition for work place policy
3) Increased loyalty of the employees to the companies mission
4) Workers are less likely to take work appointment in other places
5) Child care offering are some of the aspects workers consider when searching for jobs
6) Companies can enjoy tax breaks
Explanation:
A feather and a marble are released from a height of 10 m at the same time. Why will the marble reach the ground first
Answer:
air resistance slows the feather
Explanation:
Scientists want to place a telescope on the moon to improve their view of distant planets. The telescope weighs 200 pounds on Earth. What will happen to the weight of the telescope when it reaches the moon? The weight of the telescope will increase. The weight of the telescope will decrease. The weight of the telescope will stay the same. The weight of the telescope will be equal to its mass.
Answer:
Explanation:
the weight of the telescope decreases because the moon attract the body with less force as compared to earth due to less gravity as compared to earth
When Scientists want to place a telescope on the moon to improve their view of distant planets. The telescope weighs 200 pounds on Earth. then The weight of the telescope will decrease. therefore the correct answer is option B.
What is gravity?It can be defined as the force by which a body attracts another body towards its center as the result of the gravitational pull of one body and another, The gravity varies according to the mass and size of the body for example the force of gravity on the moon is the 1/6th times of the force of gravity on the earth.
Thus, when scientists attempt to mount a telescope on the moon in order to get a better view of far-off planets. 200 pounds are the telescope's weight on earth weight. The telescope's weight will then decrease. So, choice B is the right response.
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A ball tossed at an angle of 40° with the horizontal will go as far downrange as one tossed at the same speed at an angle of
Answer:
50°
Explanation:
Projectiles launched at complementary angles have the same range.
A car rolls down a ramp in a parking garage. The horizontal position of the car in meters over time is shown below. Graph of horizontal position x (in meters) on y axis and time (in seconds) on x axis. The initial position is -3 m at t=0 s, and the position increases linearly to 3 m at t=8 s. Then the position is constant at 3 m until t=16 s, then increases linearly to 9 m at t=24 s.
Answer:
Explanation:
At t = 0 , X = -3 m
At t = 8s , X = + 3 m .
At t = 16s , X = + 3 m
At t = 24 s , X = + 9 m
Graph is shown in the attached file .
The displacement of the car between 8 seconds and 24 seconds is 6 m.
The given parameters:
Initial position of the car, x₁ = -3 m, time = 0 sSecond displacement, x₂ = 3 m, time = 8.0 sThird displacement, x₃ = 3 m, time = 16 sFinal displacement, x₄ = 9 m, time = 24 sThe displacement of the car between 8 seconds and 24 seconds is calculated as follows;
the position of the car at 8 seconds = 3 m
the position of the car at 24 seconds = 9 m
The displacement of the car = 9m - 3m = 6 m
Thus, the displacement of the car between 8 seconds and 24 seconds is 6 m.
The complete question is below:
What would be the displacement of the car between eight seconds and 24 seconds?
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Radio waves of frequency 1.667 GHzGHz arrive at two telescopes that are connected by a computer to perform interferometry. One portion of the same wave front travels 1.260 mm farther than the other before the two signals are combined.
Required:
a. Will the two waves combine constructively or destructively?
b. Calculate the value of m for the path difference between the two signals
Explanation:
The frequency of radio waves is 1.667 GHz
One portion of the same wave front travels 1.260 mm farther than the other before the two signals are combined.
There are two conditions for interference either constructive or destructive.
For constructive interference , the path difference is n times of wavelength and for destructive interference, the path difference is (n+1/2) times of wavelength
We can find wavelength in this case as follows :
[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{1.667\times 10^9}\\\\\lambda=0.1799\ m[/tex]
If we divide path difference by wavelength,
[tex]\dfrac{\delta}{\lambda} =\dfrac{1.26}{0.1799}\\\\\dfrac{\delta}{\lambda} =7\\\\\delta =7\lambda[/tex]
It means that the path difference is 7 times of the wavelength. it means the two waves combine constructively and the value of m for the path difference between the two signals is 7.
give two application for newton's first law of motion in our daily life
Answer:
1.A driver of automobile brakes abruptly and, by inertia, shoots forward.
2. A stone in the ground is in a state of rest
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solve the equation below for vi.
d=vit +.5at2
Answer: [tex]\dfrac{d-0.5at^2}{t}=v_i[/tex]
Explanation:
[tex]d=v_it+0.5at^2\\\\\\\text{Subtract}\ 0.5at^2\ \text {from both sides:}\\d-0.5at^2=v_it\\\\\\\text{Divide both sides by t:}\\\dfrac{d-0.5at^2}{t}=v_i[/tex]
This diver has just jumped up from the end of the diving board. After she dives down and is falling toward the water, she’ll have kinetic energy, or the energy of moving matter. But even as she is momentarily stopped high above the water, she has energy. Do you know why?
Answer:
Mechanical energy is divided into two:Kinetic energy and Potential energy....The diver diving down exhibits kinetic energy because she is moving but when she has stopped it means she has potential energy which means that a body is at rest....
A boy kicks a ball with a mass of 5 kg so that it accelerates at 4 m/s2 in the forward direction.
A 40 N
B 0 N
C 20 N backward
D 20 N forward
If force is made to act on a smaller area, then the pressure will be ______________
A) The army has acquired radar that can track an artillery shell in flight and determine its origin before it hits. The system erects a sensitive electronic plane over a broad area and can detect any projectile piercing that plane. After tracking the shell and plotting its path, system's computer back tracks the trajectory to the firing location. The enemy has fired a shell at the radar station. The radar detects the shell at the coordinates (400 m, 75 m) and again at (200 m, 50 m). Given that the path of a projectile projected near the surface of the earth is a parabolic, determine (i) the angle of projection of the shell and (ii) the initial velocity of projection.
Answer:
i) angle of projection = 17.4⁰
ii) initial velocity = 131.2 m/s
Explanation:
To determine the angle of projection and initial velocity of projection we have to apply the projectile path equation
where : Vi = initial velocity , g = acceleration due to gravity , ∅ = angle of projection
attached below is the detailed solution of the problem above
Can someone tell me the answer of this question?
Answer:a 1 10th
b89 10
Explanation:
thats all i know so thank me when yoiu get them right:)
When compared to others, how is a greater velocity represented on a motion map?
Answer:
Longer legs
Explanation:
I took the test
Two technicians are discussing electromagnetic induction. Technician A says that the induced voltage can be increased if the speed is increased between the conductor and the magnetic lines of force. Technician B says that the induced voltage can be increased by increasing the strength of the magnetic field. Which technician is correct?
Answer:
Both technicians are correct
Explanation:
In electromagnetic induction, the induced voltage can be increased by increasing the relative speed between the conductor and the magnetic line of force, by increasing the strength of the magnetic field, which increases the magnetic lines of force, Increase the strength of the magnetic field, so there are more flux lines, and also by increasing the angle between the flux lines and the conductor to a maximum of 90 degrees.
Compare the structure of a lithium atom to the structure of a lithium ion
Answer:
A lithium atom has 3 protons and 3 electrons. It can lose one of its electrons, making it an ion. It now has more positive protons than electrons so it has an overall positive charge. Therefore it is a positive ion.
Answer:
If an atom gains or loses an electron, it bacomes an ion. ... A lithium atom has 3 protons and 3 electrons. It can lose one of its electrons, making it an ion. It now has more positive protons than electrons so it has an overall positive charge.
Explanation:
Please Help!! Will Give brainlest!! Four friends push on the same block in different directions. Allie pushes on the block to the north with a force of 18 N. Bill pushes on the block to the east with a force of 14 N. Chris pushes on the block to south with a force of 23 N. Debra pushes on the block to the west with a force of 20 N. Assuming it does not move vertically, in which directions will the block move?(1 point) A) south and east B) north and west C) south and west D) north and east
Answer:
South and West
Those people are pushing the hardest. It will move south faster than it moves west.
Explanation:
what is the mass calculate it if the weight of a body is 420 N .
Answer:m=42kg
Explanation:
wieght = mass × gram
420 = mass × 10
therefore , answer is 42
Answer:
[tex]\huge \boxed{\mathrm{42 \ kg} }[/tex]
Explanation:
[tex]\sf Weight \ (N) = mass \ (kg) \times acceleration \ of \ gravity \ (m/s^2)[/tex]
[tex]\sf W=m \times g[/tex]
We know that the acceleration of gravity on the Earth is approximately 10 m/s.
The weight of the body is given 420 N.
[tex]\sf 420=m \times 10[/tex]
Solve for the mass. Divide both sides by 10.
[tex]\sf m = 42[/tex]
The mass of the body is 42 kg.
8,000 mg + 2 g = _____________ mg?
Answer:
10,000 mg
Explanation: 1g= 1000mg
Therefore,
8000 mg+2000mg=10000mg
Answer:
10
Explanation:
1mg=1/1000gso 8000mg=8000/1000g