Answer:
A. When two surfaces are moving relative to each other.
Explanation:
It is also know as dynamic friction
Which of the following would NOT produce a current? A. Moving a bar magnet inside a coil of wire O B. Moving a bar magnet toward a straight wire C. Moving a straight wire toward a bar magnet O D. Placing a bar magnet next to a wire.
Answer:
c
Explanation:
Answer:C
Explanation:
Consult Interactive Solution 7.10 for a review of problem-solving skills that are involved in this problem. A stream of water strikes a stationary turbine blade horizontally, as the drawing illustrates. The incident water stream has a velocity of 16.0 m/s, while the exiting water stream has a velocity of -16.0 m/s. The mass of water per second that strikes the blade is 36.0 kg/s. Find the magnitude of the average force exerted on the water by the blade.
Answer:
[tex]F=1152N[/tex]
Explanation:
From the question we are told that:
Mass/one sec [tex]m=36.0kg/s[/tex]
Incident water stream [tex]v=16.0m/s[/tex]
Exiting water stream [tex]v'=-16.0m/s[/tex]
Generally the equation for Force is mathematically given by
[tex]F=\frac{mv-mu}{t}[/tex]
[tex]F=\frac{36(-16-16)}{1}[/tex]
[tex]F=1152N[/tex]
kinetic energy is associated with energy
True or false
Answer:
true ,the kinetic energy is associated with energy
An electric generator has an 18-cmcm-diameter, 120-turn coil that rotates at 60 HzHz in a uniform magnetic field that is perpendicular to the rotation axis. Part A What magnetic field strength is needed to generate a peak voltage of 330 VV
Explanation:
OK ok nosepo [tex]2825.55[/tex]The magnetic field strength is needed to generate a peak voltage is 0.287 T.
The given parameters;
diameter of the generator, d = 18 cm = 0.18number of turn, N = 120 turnfrequency of the coil, f = 60 Hzmaximum voltage in the coil emf = 330 V;The maximum voltage in the coil is calculated as follows;
[tex]E_{max} = NAB\omega \\\\[/tex]
where;
N is the number of turnsA is the area of the coilB is the magnetic field strengthω is angular speedThe magnetic field strength is needed to generate a peak voltage is calculated as;
[tex]B = \frac{E_{max} }{NA \omega } \\\\B = \frac{E_{max} }{N (\frac{\pi d^2}{4} ) \times 2\pi f}\\\\ B = \frac{330}{120 \times (\frac{\pi \times 0.18^2}{4} ) \times 2\pi \times 60} \\\\B = 0.287 \ T[/tex]
Thus, the magnetic field strength is needed to generate a peak voltage is 0.287 T.
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Ftension
120 N
10 kg
Fg
What is the net force on the box?
O 22 Newtons upward
120 Newtons upward
O 98 Newtons downward
O O Newtons
Answer:
120N Hacia arriba
The strength of a magnetic field around a wire carrying a current of 20 A is 0.004 T. What is the strength of the
magnetic field if the current is changed to 40 A?
A 0.002 T
B 0.004 T
C 0.006 T
D 0.008 T
Answer:
D) 0.008
Explanation:
I just did it on Edg22 and I got it correct :D (Picture above)
Option D) 0.008T is the correct answer.
Hence, if the current is increased to the given value, the strength of the magnetic field around the wire carrying the current increases to 0.008T
Given the data in the question;
First scenario
Strength of magnetic field; [tex]B = 0.004T[/tex]Current; [tex]I = 20A[/tex]Second scenario
Strength of magnetic field; [tex]B' =\ ?[/tex]Current; [tex]I' = 40A[/tex]Magnetic FieldMagnetic field is a vector field or region around a magnet or electric charge upon which magnetic force is exerted.
To determine the strength of the magnetic field if the current is changed, we equate the two scenario.
[tex]\frac{B}{I} = \frac{B'}{I'}[/tex]
We substitute our given values into the expression
[tex]\frac{0.004T}{20A} = \frac{B'}{40A}\\ \\ B' * 20A = 0.004T * 40A\\\\B' = \frac{0.004T * 40A}{20A} \\\\B' = \frac{0.004T * 40}{20}\\ \\B' = \frac{0.16T}{20}\\ \\B' = 0.008T[/tex]
Option D) 0.008T is the correct answer.
Hence, if the current is increased to the given value, the strength of the magnetic field around the wire carrying the current increases to 0.008T
Learn more about magnetic field here: https://brainly.com/question/15695203
With the frequency set at the mid-point of the slider and the amplitude set at the mid-point of the slider, approximately how many grid marks is the wavelength of the wave (use the pause button and step button as you need to in order to get a good measure, and round to the nearest whole grid mark)?
If the amplitude is increased the wavelength:___________.
a. decreases
b. stays the same
c. increases
Answer:
correct answer is b
Explanation:
The frequency of a wave depends on the properties of medium density and the elasticity properties change the amplitude depends on the energy carried by the wave, that is, the amplitude is proportional to the height of the wave (oscillation).
Consequently the amplitude of independent of the frequency because it depends on different factors.
Therefore when changing the amplitude the wavelength remains constant
the correct answer is b
DL: Activity 2.3 Resistance Complete the questions based on the Resistance presentation. a. All resistors ___________ or _____________ the flow of electrons. b. As resistance __________________ current _______________________
DL: Activity 2.3 Resistance
Complete the questions based on the Resistance presentation.
a. All resistors ___________ or _____________ the flow of electrons.
b. As resistance __________________ current _______________________
Answer:a) limits or opposes
b) increases, decreases
Explanation:Resistors are electrical devices used to resist, limit, oppose or hinder the flow of electrons in a circuit. This resistance causes a reduction in current and an increase in voltage in the circuit. In order words, as resistance increases, the current decreases and voltage increases.
This was further stated by Ohm's law that states that as long as the resistance in a wire/conductor remains constant, the voltage across it is directly proportional to the current flowing through a conductor. i.e
V = IR
Where;
R = constant called resistance
I = current flowing through the wire
V = voltage across the wire
Does every magnet have a north and south pole?
yes
no
What is the average speed (in km/h) of Zhana, who runs to the store that is 4.0 km away in 30.0 minutes?
0.13 km/ h
8.0 km/h
2.0 km/h
Answer:
2.0km/h.
Explanation:
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A gazelle is running at a constant speed of 19.3 m/s toward a motionless hidden cheetah. At the instant the gazelle passes the cheetah, the cheetah accelerates at a rate of 7.1 m/s/s in pursuit of the gazelle. The gazelle maintains its constant speed. By the time the cheetah reaches a speed of 19.3 m/s to match the gazelle, how far apart are the two animals in units of m
Answer:
the animals are 26.2 meters apart.
Explanation:
Let's define t = 0s as the moment when the cheetah starts accelerating.
The gazelle moves with constant velocity, thus, it is not accelerating, then the acceleration of the gazelle is:
a₁(t) = 0m/s^2
where I will use the subscript "1" to refer to the gazelle and "2" to refer to the cheetah.
for the velocity of the gazelle we just integrate over time to get:
v₁(t) = V0
where V0 is the initial speed of the gazelle, which we know is 19.3 m/s
v₁(t) = 19.3 m/s
To get the position of the gazelle we integrate again:
p₁(t) = ( 19.3 m/s)*t + P0
where P0 is the position of the gazelle at t = 0s, let's define P0 = 0m
p₁(t) = ( 19.3 m/s)*t
The equations that describe the motion of the gazelle are:
a₁(t) = 0m/s^2
v₁(t) = 19.3 m/s
p₁(t) = ( 19.3 m/s)*t
Now let's do the same for the cheetah.
We know that its acceleration is 7.1 m/s^2
then:
a₂(t) = 7.1 m/s^2
for the velocity of the cheetah we integrate:
v₂(t) = (7.1 m/s^2)*t + V0
where v0 is the initial velocity of the cheetah, which we know its zero.
v₂(t) = (7.1 m/s^2)*t
Finally, for the position equation we integrate again, and remember that we have defined the initial position for the gazelle as zero, then the same happens for the cheetah.
p₂(t) = (1/2)*(7.1 m/s^2)*t^2
The equations for the cheetah are:
a₂(t) = 7.1 m/s^2
v₂(t) = (7.1 m/s^2)*t
p₂(t) = (1/2)*(7.1 m/s^2)*t^2
Now, we want to find the distance between both animals when the speed of the cheetah is 19.3 m/s, then first we need to solve:
v₂(t) = (7.1 m/s^2)*t = 19.3 m/s
t = (19.3 m/s)/(7.1 m/s^2) = 2.72s
Now, to find the distance between the two animals, we just compute the difference between the position equations for t = 2.72s
Distance = p₁(2.72s) - p₂(2.72s)
= ( 19.3 m/s)*2.72s - (1/2)*(7.1 m/s^2)*(2.72s)^2
= 26.2 m
So the animals are 26.2 meters apart.
Ftension = 120 N
10 kg
Fg
What is the weight (not mass) of the box?
O 10 kg
0 19 N
98 N
O 98 kg
PLZ HELP
Answer:
98N
Explanation:
El peso se mide en kg y la fuerza no afecta
A truck on a straight road starts from rest, accelerating at 2.00m/s^2 until it reaches a speed of 20.0m/s. Then the truck travels for 20.0s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5.00s.
(a) How long is the truck in motion?
(b) What is the average velocity of the truck for the motion described?
Answer:
Explanation:
a )
Time to reach the speed of 20 m/s with an acceleration of 2 m/s² can be calculated as follows .
v = u + a t
20 = 0 + 2 t
t = 20 /2 = 10 s .
Total time = 10 s + 20 s + 5 s = 35 s .
b) Average velocity = Total distance travelled / total time
Distance travelled in first 10 s
S₁ = ut + 1/2 a t²
= 0 + .5 x 2 x 10²
= 100 m
Distance travelled in next 20 s
S₂= 20s x 20 m/s = 400 m
Distance travelled in last 5 s .
deceleration in last 5 s
v = u + at
0 = 20 m/s + a x 5
a = - 4 m/s²
v² = u² - 2 a s
0 = (20 m/s)² - 2 x 4 m/s² x s
s = 50 m
S₃ = 50 m
Total distance = S₁ + S₂ + S₃
= 100 m + 400 m + 50 m
= 550 m .
Average velocity = 550 m / 35 s
= 15.71 m /s .
A 0.200 m wire is moved parallel to a 0.500 T
magnetic field at a speed of 1.50 m/s. What emf is
induced across the ends of the wire?
Answer:
The required emf moved across the wire is zero
Explanation:
For a moving charge particle, the magnetic force can be determined by using the formula;
[tex]\varepsilon = Bvlsin \theta[/tex]
since the wire moves in parallel, the angle [tex]\theta[/tex] between magnetic field and velocity = 0°
B = 0.500 T
v = 1.50 m/s
l = 0.200 m
∴
[tex]\varepsilon = (0.500 \ T )(1.50 \ m/s) \times (0.200 \ m)\times sin (0)[/tex]
[tex]\varepsilon = 0.15\times sin (0)[/tex]
[tex]\varepsilon = 0[/tex]
Subtract the following numbers, using scientific notation and the correct number of significant digits.
6.94 × 103 mm - 4.5 × 102 mm = _____.
2.4 × 103 mm
2.44 × 102mm
6.49 × 103 mm
6.5 × 103 mm
Answer:
The correct answer is - 6.49 × 10^3 mm.
Explanation:
The correct scientific notation of the given subtraction problem is:
6.94 × 10^3 mm - 4.5 × 10^2 mm = _____.
The correct number of significant digits is
a. 6.94 × 10^3 mm = 3
b. 4.5 × 10^2 mm = 2
So subtracting the 6.94 × 10^3 mm - 4.5 × 10^2 mm
= 6940 - 450
= 6.49× 10^3 mm.
Answer:
6.5x 10^3 mm
Explanation:
During a long jump, an Olympic champion's center of mass rose about 1.2 m from the launch point to the top of the arc. 1) What minimum speed did he need at launch if he was traveling at 6.8 m/s at the top of the arc
Answer: Minimum speed needed by the Olympic champion at launch if he was traveling at 6.8 m/s at the top of the arc is 11.65 m/s.
Explanation:
Velocity is only in horizontal direction at the top most point which is similar to the velocity in the horizontal direction at the time of launch.
Now, according to the law of conservation of energy the formula used is as follows.
[tex]mgh = \frac{1}{2} mv^{2}_{y}\\v_{y} = \sqrt{2gh}\\= \sqrt{2 \times 9.8 m/s^{2} \times 1.2}\\= 4.85 m/s[/tex]
As speed at which the person is travelling was 6.8 m/s. Hence, the initial velocity will be calculated as follows.
[tex]v = \sqrt{v^{2}_{x} + v^{2}_{y}}\\= \sqrt{(6.8)^{2} + (4.85 m/s)^{2}}\\= 11.65 m/s[/tex]
Thus, we can conclude that minimum speed needed by the Olympic champion at launch if he was traveling at 6.8 m/s at the top of the arc is 11.65 m/s.
Which element is the biggest contributor to Climate Change?
Answer:
carbon dioxide (CO2)
Explanation:
the burning or combustion of these fossil fuels creates gases that are released into the atmosphere. Of these gases, carbon dioxide (CO2) is the most common and is the gas most responsible for exacerbating the green- house effect that is changing global climate patterns.
An astronaut weighing 248 lbs on Earth is on a mission to the Moon and Mars. (a) What would he weigh in newtons when he is on the Moon
Answer:
[tex]W_m=183.495N[/tex]
Explanation:
From the question we are told that:
Weight [tex]W=248Ibs[/tex]
Mass of Weight [tex]m= 248*0.453[/tex]
[tex]m=112.344kg[/tex]
Generally the acceleration due to gravity on the Moon is one-sixth that on Earth.
Therefore
The equation for Weight on Moon is given as
[tex]W_m=m*g/6[/tex]
[tex]W_m=122.344*\frac{9.8}{6}[/tex]
[tex]W_m=183.495N[/tex]
Answer:
F ’= 40.9 lb
Explanation:
The weight of a body is the attraction of the Earth on the body
F = [tex]G \frac{m M_e}{R_e^2}[/tex]
F = mg
m = F / g
m = 248/32
m = 7.75 slug
The weight of the body on the moon is the attraction of the body for the satellite
F ’= [tex]G \frac{mM}{R^2}[/tex]
from the tables the mass and radius of the moon are M = 7.34 10²² kg and R = 1.74 10⁶ m
let's reduce the mass to the SI system
m = 7.75 slug (14.59 kg / 1 slug) = 113 kg
F ’= 6.67 10⁻¹¹ 113 7.34 10²² / (1.74 10⁶) ²
F ’= 1.82 10² N
F ’= 1.82 10² N (0.2248 lb / 1 N)
F ’= 40.9 lb
At what frequency would an inductor of inductance 0.8H have a reactance of 12000^?
Explanation:
The inductive reactance [tex]X_L[/tex] is given by
[tex]X_L = \omega L = 2 \pi fL[/tex]
Solving for f, we get
[tex]f = \dfrac{X_L}{2 \pi L} = \dfrac{12000\:\text{ ohms}}{2\pi (0.8\:H)}[/tex]
[tex]\:\:\:\:\:\:\:= 2387.3\:\text{Hz}[/tex]
Which of the following is an expression of Newton's second law? A. The acceleration of an object is determined by its mass and the net force acting on it. O O B. Objects at rest tend to stay at rest and objects in motion tend to stay in motion unless acted on by an unbalanced force. C. Objects at rest tend to stay at rest, and objects in motion tend to slow down until they come to rest. D. Every force is paired with an equal and opposite force.
Answer: A. The acceleration of an object is determined by its mass and the net force acting on it.
Explanation:
Newton's second law of motion explains that the acceleration of an object will depend on two vital variables which are the mass of the object and the net force that's acting on it.
It should be noted that the acceleration of the object directly depend on the net force while it depends inversely on the mass. Therefore, when the force that's acting on such object is increased, then the acceleration will increase as well. On the other hand, when there is an increase in mass, there'll be a reduction in the acceleration.
write the full form of MBBS pliz now
Answer:
The full form of MBBS is Bachelor of Medicine, Bachelor of Surgery
pls mark me brainliest :))
The full form of MBBS in India is 'Bachelor of Medicine, Bachelor of Surgery'. However, MBBS is an abbreviation of Medicinae Baccalaureus Baccalaureus Chirurgiae, which is the term used for this course in Latin.
4.Upthrust doesnt depend on the following Physical quantity?
volume of body
density of body
mass of body
acceleration due to gravity
Answer:
C: Mass of body
Explanation:
Upthrust is defined as the upward force that a liquid will exert on a body floating atop it.
Now, Formula for upthrust is;
Upthrust = density of liquid × volume of the body × acceleration due to gravity.
From the formula, we can see that upthrust depends on density, volume and acceleration due to gravity.
Thus, looking at the options, the one that doesn't apply is mass of body.
What is the vibrating source that creates sound waves?
Answer:
Sound is produced when an object vibrates, creating a pressure wave. This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. As the particles vibrate, they move nearby particles, transmitting the sound further through the medium.
Preocupada com o aumento da tarifa na conta de luz, uma pessoa resolve economizar diminuindo o tempo de banho de 20 para 15 minutos. Seu chuveiro possui as seguintes especificações: 4200 W e 220V. Sabendo que o kWh custa R$0,30, a economia feita em 10 dias foi de aproximadamente
A wave with a frequency of 60 hertz would generate 60 wave crests every
Answer:
A wave with a frequency of 60 hertz will have 60 successive wave crests occurring every second
Explanation:
A crest is the highest point the medium rises to in a wave. That means that the crest is a point on the wave where the displacement is at a maximum.
Frequency is the number of oscillations of a wave in one second. Hence, frequency of a wave is the number of successive crests occurring in a second.
Therefore a wave with a frequency of 60 hertz will have 60 successive wave crests occurring every second.
Calculate the pressure exerted on the floor when an
elephant who weighs 2400N stands on one foot which has
an area of 4m²?
P = F / A
P = 2400 / 4
P = 24 × 100 / 4
P = 6 × 100
P = 600 N/m^2
a typical cmall flashlight contains two batteries each having na emf of 2.0 v connected in series with a bulb havin ga resistance of 16 ohms if the internal resistance of the batteries is negligible what power is delivered to the ublb
Answer:
P = 0.25 W
Explanation:
Given that,
The emf of the battry, E = 2 V
The resistance of a bulb, R = 16 ohms
We need to find the power delivered to the bulb. We know that, the formula for the power delivered is given by :
[tex]P=\dfrac{V^2}{R}\\\\P=\dfrac{2^2}{16}\\\\=0.25\ W[/tex]
So, 0.25 W power is delivered to the bulb.
What is the gain in gravitational potential energy of a body of weight 2000N as it rises from a height of 20m to a height of 25 m above the Earth's surface
Answer:
Explanation:
GPE =weight * height
= 2000*(25-20)
= 10000 J
Gain of Gravitation Potential energy = 10,000 J
What is Gravitation Potential Energy ?
It is the energy acquired by an object due to a change in its position when it is present in a gravitational field .
To calculate gravitational potential energy at height h , formula used is = m g h where m = mass of the body
g = acceleration due to gravity
h = height from the ground
Gain of Gravitation Potential energy = mg(h2 - h1 ) h2 = final height
h1 = initial height
= 2000 (25 -20) (since , mg =weight)
Gain of Gravitation Potential energy = 10,000 J
Learn more about Gravitation Potential energy :
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A ball of mass=2kg is dropped from h=100m. What is the final velocity when it reaches the ground? *
A)45m/s
B)200m/s
C)32m/s
D)2000m/s
show your work please
Answer:
45m/s
Explanation:
(here I'm taking gravity due to acceleration as 10 m/s^2 and not 9.8 m/s^2 to match the options)
We know that when an object is dropped from a certain height it has initial velocity 0 m/s
so;
u= 0m/s
s= 100m
a= 10m/s^2
Using 4th law of motion;
v^2 - u^2 = 2× a× s
v^2 - 0^2 = 2 × 10 × 100
v^2 = 2000
v = √2000
v = 44.72 m/ s
Final velocity = 45 m/ s (rounding off to 45)
Please feel free to tell me if you have any confusion.
what is parallelogram law of vector addition ???
Answer:
According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex
Explanation: