Complete question:
A 40-turn coil has a diameter of 17 cm. The coil is placed in a spatially uniform magnetic field of magnitude 0.40 T so that the face of the coil and the magnetic field are perpendicular. Find the magnitude of the emf induced in the coil (in V) if the magnetic field is reduced to zero uniformly in the following times. (a) 0.10 s, (b) 1.0 s, and (c) 60 s.
Answer:
(a) E = 3.632 V
(b) E = 0.3632 V
(c) E = 6.053 mV
Explanation:
Given;
number of turn of the coil, N = 40 turn
diameter of the coil, d = 17 cm = 0.17 m
radius of the coil, r = d /2 = 0.17 /2 = 0.085 m
initial magnitude of magnetic field, B₁ = 0.4 T
final magnitude of magnetic field, B₂ = 0
The induced emf in the coil is given by;
[tex]E = -N\frac{dB}{dt} A = \frac{-NA(B_2 - B_1)}{dt} =\frac{NA(B_1-B_2)}{dt} =\frac{NAB_1}{t}[/tex]
A is area of the coil = πr² = π(0.085)² = 0.0227 m²
(a) when the time is 0.1 s
[tex]E= \frac{40*0.0227*0.4}{0.1} = 3.632 \ V[/tex]
(b) when the time is 1 s
[tex]E = \frac{40*0.0227*0.4}{1} \\\\E = 0.3632 \ V[/tex]
(c) when the time is 60 s
[tex]E = \frac{40*0.0227*0.4}{60} \\\\E = 6.053 \ mV[/tex]
What magnetic field strength will allow the electrons to pass through without being deflected?
Answer:
Explanation:
If magnetic field exists parallel to the direction of motion of electron , no force will act on the electrons and hence there will be no deflection in them .
In such cases , the magnitude of magnetic field is immaterial . No matter how high or low magnitude of magnetic field be , if it is parallel to the velocity of electron , it will not be deflected as the force created on them will be zero.
Only in case magnetic field makes some angle with the direction of velocity , force will be created and electron will be deflected .
A paper pinwheel is spinning in the wind. Which statement is correct about the forces responsible for the rotation?
A paper pinwheel is spinning in the wind.
Which statement is correct about the forces responsible for the rotation?
The components of gravity and the force of wind that point through the pivot are responsible for the rotation.
Only the perpendicular component of wind is responsible for the rotation, because gravity points downward.
Only the perpendicular component of gravity is responsible for the rotation, because wind points toward the pivot.
The perpendicular components of gravity and the force of wind are responsible for the rotation.
Answer:
Only the perpendicular component of gravity is responsible for the rotation because wind points toward the pivot.
Explanation:
A pinwheel is a plaything that is made up of paper that is designed to spin when the wind comes in contact with it. The paper is held fast to its axle by a pin which enables it to spin.
Therefore, if the pinwheel is spun anti-clockwise, it brings electrical energy, converting the wind energy and only the perpendicular component of gravity is responsible for the rotation because wind points toward the pivot.
What is a property of “normal force”? a. It always points perpendicular to the contact surface. b. It always points parallel to the contact surface. c. It always points up. d. It always completely counters gravity.
Answer:
a. It always points perpendicular to the contact surface.
Explanation:
"Normal" means perpendicular. Normal forces are always perpendicular to the contact surface.
an astronaut is said to be weightless when he/she travells in a satellite . does it mean that the earthdoes not attract him/her ?
Answer:
It does attract
Explanation:
But due to the lack of gravitational pull of the earth he/she feels weightless I hope this helps you
Given 1ft = 12in, how many feet are in 36 inches?
Answer:
Hey there!
1 ft= 12 inches
3 ft= 36 inches.
Let me know if this helps :)
Answer: 3
The formula is to divide by 12
36÷12=3
1ft = 12in
A uniform disk a uniform hoop and a uniform sphere are released at the same time at the top of an inclined ramp. They all roll without slipping in what order do they reach the bottom of the ramp?
a. disk hoop, sphere
b. sphere, hoop, disk
c. hoop, sphere, disk
d. sphere, disk, hoop
e. hoop, disk, sphere
Two resistors connected in parallel, with R1 = 150 ohms and R2 = 75 ohms, are connected to a battery that experiences a current of 0.18 A. The current through R1 is _____ A.
Answer:
Explanation:
Given:
Two resistors (Parallel)
R1 = 150 ohms
R2 = 75 ohm
Current (I) = 0.18 A
Find:
Current through R1
Computation:
Common resistance
1/R = 1/R1 + 1/R2
1/R = 1/150 + 1/ 75
R = 50 ohms
V = IR
V = 0.18 x 50
V = 9v
So,
V = IR1
9 = I (150)
Current through R1 = 9 / 150
Current through R1 = 0.06 A
A cruise started its trip 8:00. Its average speed was 100 km/h.
When it travelled 2/5 of its journey by 12:00, the boat changed
its speed. If the boat was required to arrive at the destination at
17:00, what average speed must the boat travel at for the
remaining journey?
Answer:
120 k/m
Explanation:
Answer: 120
Explanation:
A person speed walking down a street covers 20m in 5s. What is the
speed of the individual? *
Answer:
4 m/s.
Explanation:
The following data were obtained from the question:
Distance travalled (d) = 20 m
Time (t) = 5 secs
Speed (S) =?
Speed is defined as the rate of change of distance moved with time. Mathematically, it is expressed as:
Speed (S) = Distance (d) /time (t)
S = d/t
With the above formula, we can easily calculate the speed of the individual as follow:
Distance travalled (d) = 20 m
Time (t) = 5 secs
Speed (S) =?
S = d/t
S = 20/5
S = 4 m/s
Therefore, the speed of the individual is 4 m/s
A very long straight current-carrying wire produces a magnetic field of 20 mT at a distance d from the wire. To measure a field of 5 mT due to this wire, you would have to go to a distance from the wire of
A- 4d.
B - 16d.
C - d sqrt2
D- 8d.
E- 2d.
Answer:
A. 4d
Explanation:
Magnetic field strength is inversely proportional to distance. So in order to have a smaller magnetic field, we need to move further out from the wire. How far we go exactly can be determined from the formula: B=(μ₀I)/(2πr)
(That is derived from Ampere's Law, which states ∫B•dl=μ₀I)
With that you can set up a ratio between the magnetic fields in both cases. Because the current is the same for both instances, everything reduces out on one side of the equation and leaves you with something that relates the two distances by a ratio of each magnetic field value.
My work is in the attachment, comment for questions.
When landing after a spectacular somersault, a 41 kg gymnast decelerates by pushing straight down on the mat. Calculate the force she must exert if her deceleration is 7.00 times the acceleration due to gravity. Explicitly show how you follow the steps in the Problem-Solving Strategy for Newton's laws of motion.
Answer:
The force the gymnast must exert is 2812.6 N.
Explanation:
Given;
mass of the gymnast, m = 41 kg
her deceleration, -a = 7g = 7 x 9.8m/s² = 68.6 m/s²
Apply Newton's second law of motion;
F = ma
where;
F is the magnitude of the force exerted
m is the mass of the gymnast
a is the deceleration
Substitute in the given values of m and a into the force equation;
F = ma
F = 41 x 68.6
F = 2812.6 N
Therefore, the force the gymnast must exert is 2812.6 N.
Train A is moving at 100 kmh–1 through a station. Train B is also travelling at 100 kmh–1 through the station but in the opposite direction to train A. What is the speed of a seated passenger on? (a) train A relative to an observer on the station? (b) train A relative to another seated passenger on the same train? (c) train B relative to a passenger on train A?
Explanation:
(a) An observer on the station has a speed of 0 km/h. The speed of a passenger on Train A is 100 km/h. The relative speed is 100 km/h − 0 km/h = 100 km/h.
(b) The speed of both passengers is 100 km/h, in the same direction. The relative speed is 100 km/h − 100 km/h = 0 km/h.
(c) The speed of both passengers is 100 km/h, in opposite directions. The relative speed is 100 km/h − (-100 km/h) = 200 km/h.
Can someone solve the blank questions? I am really having trouble solving them. Thank you!
Answer:
<In the attachment>
Explanation:
There's not really much for me to say here I feel. On 7)b) you appear to let y=0 for some reason, so I redid that one without doing that just in case. Just look at what I did and take notes for the future.
what is the percent uncertainty in the volume of a spherical beach ball whose radius is r = .84 plus or minus .04 m?
Answer:
The percent uncertainty in the volume [tex]\frac{\delta V}{V} * 100 = 14.286\%[/tex]
Explanation:
From the question we are told that
The radius is [tex]r = 0.84 \pm 0.04 \ m[/tex]
From the given value
The uncertainty of radius is [tex]\delta r = 0.04[/tex]
Generally the volume of a spherical beach ball is mathematically represented as
[tex]V = \frac{4\pi }{3}* r^3[/tex]
Now taking the log of both sides
[tex]log V = log [\frac{4\pi}{3} ] * r^3[/tex]
=> [tex]log V = log [\frac{4\pi}{3} ] + log( r^3)[/tex]
=> [tex]log V = log [\frac{4\pi}{3} ] + 3log( r)[/tex]
Differentiating both sides
[tex]\frac{1}{V} \delta V = 0 + 3 [\frac{1}{r} ] \ \delta r[/tex]
Now converting them to percentage by multiplying by 100
[tex]\frac{\delta V}{V} * 100 = [\frac{ 3 \delta r }{r} ] \ * 100[/tex]
=> [tex]\frac{\delta V}{V} * 100 = [\frac{ 3 * 0.04 }{ 0.84} ] \ * 100[/tex]
=> [tex]\frac{\delta V}{V} * 100 = 14.286\%[/tex]
You throw a balloon that floats in the air with a velocity of 2 m / s south . If the wind speed is 5 m / s west , how far south will the balloon travel after 2 seconds ?
Answer:
The distance traveled by the balloon is 10.77 m
Explanation:
velocity of the ball, [tex]v_b[/tex] = 2 m/s south
velocity of the air, [tex]v_a[/tex] = 5 m/s west
To determine the distance the balloon will travel after 2 seconds, first determine the resultant velocity of the balloon.
| 2m/s
|
|
↓
5m/s ←------------------
the two velocities forms a right angled triangle and the resultant will be the hypotenuses side of the triangle.
R² = 5² + 2²
R² = 29
R = √29
R = 5.385 m/s
The distance traveled by the balloon is calculated as;
d = R x t
where;
t is time of the motion = 2 seconds
d = 5.385 x 2
d = 10.77 m
Therefore, the distance traveled by the balloon is 10.77 m.
A ruby laser delivers a 16.0-ns pulse of 4.20-MW average power. If the photons have a wavelength of 694.3 nm, how many are contained in the pulse
Answer:
The value is [tex]n = 2.347 *10^{17} \ photons[/tex]
Explanation:
From the question we are told that
The amount of power delivered is [tex]P = 4.20 \ M W = 4.20 *10^{6} \ W[/tex]
The time taken is [tex]t = 16.0ns = 16.0 *10^{-9} \ s[/tex]
The wavelength is [tex]\lambda = 694.3 \ nm = 694.3 *10^{-9} \ m[/tex]
Generally the energy delivered is mathematically represented as
[tex]E = P * t = \frac{n * h * c }{\lambda }[/tex]
Where [tex]h[/tex] is the Planck's constant with value [tex]h = 6.262 *10^{-34} \ J \cdot s[/tex]
c is the speed of light with value [tex]c = 3.0*10^{8} \ m/s[/tex]
So
[tex]4.20 *10^{6} * 16*10^{-9}= \frac{n * 6.626 *10^{-34} * 3.0*10^{8} }{694.3 *10^{-9}}[/tex]
=> [tex]n = 2.347 *10^{17} \ photons[/tex]
Jane is sliding down a slide. What kind of motion is she demonstrating? A. translational motion B. rotational motion C. vibrational motion D. transverse motion
Answer:
Transational Motion
Explanation:
An 8-hour exposure to a sound intensity level of 90.0 dB may cause hearing damage. What energy in joules falls on a 0.800-cm-diameter eardrum so exposed?
Answer:
1.4E-3J
Explanation:
Given that
Time = 8hrs = 28.8E3 seconds
Intensity= 90dB
D= 0.008m
Radius= 0.004m
So intensity is sound level Bis
10dBlog(I/Io)
I= 10 (B/10dB)Io
= 10( 90/10) x 10^-12
=0.001W/m²
But we know that
I = P/A
P= I πr²
= 5.02 x10^-8W
But energy is power x time
So E= 5.02E-8 x 28.8E3
= 1.4E-3J
Answer:
1.44x10⁻³J
Explanation:
Given :
Time = 8hrs *(3600secs/1hr)= 28.8*10³seconds
Intensity= 90dB
D= 0.008m
Radius=0.008m/2
=0.004m
the sound level in decibel can be expressed below as
I=10dBlog[I/I₀]
where I₀=10⁻¹²/m² which is the refrence intensity
90=10log[I/10⁻¹²]
I=0.001W/m²
we know that intensity of the wave which id the average rate per unit area which energy is transfered can be calculated using below formular
I = P/A
where P= powerr which is renergy transfer at a time
A= area= πr²
making P subject of formular we have
P= I πr²
= 5.02 x10⁻⁸W
Energy =power x time
E=28800*5*10⁻⁸
=0.001443J
therefore,the energy in joules is 1.44x10⁻³J
To initiate a nuclear reaction, an experimental nuclear physicist wants to shoot a proton into a 5.50-fm-diameter 12C nucleus. The proton must impact the nucleus with a kinetic energy of 1.80 MeV. Assume the nucleus remains at rest.
Required:
a. With what speed must the proton be fired toward the target?
b. Through what potential difference must the proton be accelerated from rest to acquire this speed?
Answer:
Explanation:
kinetic energy required = 1.80 MeV
= 1.8 x 10⁶ x 1.6 x 10⁻¹⁹ J
= 2.88 x 10⁻¹³ J
If v be the velocity of proton
1/2 x mass of proton x v² = 2.88 x 10⁻¹³
= .5 x 1.67 x 10⁻²⁷ x v² = 2.88 x 10⁻¹³
v² = 3.45 x 10¹⁴
v = 1.86 x 10⁷ m /s
If V be the potential difference required
V x e = kinetic energy . where e is charge on proton .
V x 1.6 x 10⁻¹⁹ = 2.88 x 10⁻¹³
V = 1.8 x 10⁶ volt .
Mass on a Spring: A 0.150-kg air track cart is attached to an ideal spring with a force constant (spring constant) of 3.58 N/m and undergoes simple harmonic oscillations. What is the period of the oscillations
Answer:
The period is [tex]T = 1.286 \ s[/tex]
Explanation:
From the question we are told that
The mass of the spring is [tex]m = 0.150 \ kg[/tex]
The spring constant is [tex]k = 3.58 \ N/m[/tex]
Generally the period is mathematically represented as
[tex]T = 2 \pi \sqrt{ \frac{m}{k} }[/tex]
substituting values
[tex]T = 2 \pi \sqrt{ \frac{ 0.150}{3.58} }[/tex]
[tex]T = 1.286 \ s[/tex]
Two cars collide head on while each is traveling at 60km/h .Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car?You can assume that each car's specific heat is that of iron.
Answer:
The temperature rise [tex]\Delta T = 0.3088 \ ^oC[/tex]
Explanation:
From the question we are told that
The speed is [tex]v = 60 \ km /h = 16.67 \ m/s[/tex]
Generally according to the law of energy conservation we have that
The kinetic energy = increase in the internal energy of the car
i,e [tex]\frac{1}{2} * m * v^2 = m * c_p * \Delta T[/tex]
Here [tex]c_p[/tex] of iron is [tex]c_p = 450 \ J/kg K[/tex]
So
[tex]0.5 * 16.67^2 = 450 * \Delta T[/tex]
=> [tex]\Delta T = 0.3088 \ ^oC[/tex]
The temperature increase of each car will be 0.3088 °C.
What is temperature?Temperature directs to the hotness or coldness of a body. In clear terms, it is the method of finding the kinetic energy of particles within an entity. Faster the motion of particles more the temperature.
The given data in the problem is;
v is the velocity= 60 km/h=16.67 m/sec
ΔT is the temperature difference=?
[tex]\rm c_P[/tex] is the specific heat of iron=450 J/KgK
From the law of energy conservation of the energy, the kinetic energy is equal to the increase in the internal energy of the car.
[tex]\rm KE=\triangle E \\\\\ \frac{1}{2} mv^2=mc_p \triangle T \\\\ \triangle T=\frac{v^2}{2C_p} \\\\\ \triangle T=\frac{(16.67)^2}{2\times 450} \\\\ \triangle T=0.3088 ^0\C[/tex]
Hence the temperature increase of each car will be 0.3088 °C.
To learn more about the temperature refer to the link;
https://brainly.com/question/7510619Δ
A tank 20 m deep and 7m wide is layered with 8m of oil,6m of water and 5m of mercury.complete total hydroatatic force.(density of oil and mercury is 800 and 13600kg/m respectively ).
Answer:
F = 3.03 10⁷ N
Explanation:
We will eat by calculating the pressure in the tank
P = ρ g h
the pressure totals the sum of the pressure of each liquid
P_total = P_oil + P_water + P_Hg
P_total = ρ_oil g h_oil + ρ_water g h_water + ρ_Hg g h_Hg
P_total = g (ρ_oil h_oil + ρ_water h_water + ρ_Hg h_Hg)
P_total = 9.8 (800 8 + 1000 6 + 13 600 5)
P_total = 7,879 10⁵ Pa
The definition of Pressure is
P = F / A
F = P A
The area of a tank is the area of a circle
A = π r² = π d² / 4
F = P π d² / 4
let's calculate
F = 7,879 10⁵ π 7²/4
F = 3.03 10⁷ N
In this calculation the atmospheric pressure was not taken into account because they ask the hydrostatic pressure
Which of these particles are equal in number when an atom is neutral?
A. protons, neutrons
B. protons, electrons
C. neutrons, electrons
D. protons, neutrons, electrons
You slide a coin across the floor, and observe that it slows down and eventually stops. A sensitive thermometer shows that its temperature increased. What can we conclude
Answer:
The mechanical energy of the coin has been used up in doing work against friction.
Explanation:
When two bodies in contact move against one another, friction comes to play. Friction converts energy in such a system to heat which raises the temperature of the body, with most lost to the ambient environment. Sliding the coins on the floor transfers energy from your hand into the mechanical energy of the coin as it moves across the floor. Fiction between the coin and the surface of the floor gradually slows the coin down by converting its energy to heat (which raises the temperature of the coin as detected by the thermometer) until the coin comes to a halt.
When a p-n-p transistor is operated in saturation region, then its ___________
Answer:
Base-emitter and Base-collector junctions are forward biased
Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v
Answer:
264 m
Explanation:
The complete question is
Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v = 0.75c
using the length contraction relationship,
[tex]l = l_{0} \sqrt{1 - \beta ^{2} }[/tex]
where [tex]\beta = \frac{v}{c}[/tex]
[tex]l[/tex] is the relativistic length
[tex]l_{0}[/tex] is the actual length = 400 m
v is the velocity of the spaceship
c is the speed of light
since v = 0.75c
v/c = 0.75
substituting, we have
[tex]l = 400 * \sqrt{1 - 0.75 ^{2} }[/tex] = 400 x 0.66 = 264 m
plz solve this. plz plz plz plz simple machine
Answer:
Explanation:
i. CW moment = 10 N (10 cm) + 30 N (30 cm) - 60 N (40 cm) = - 1400 N-cm
ii. ACW momenet = 60 N (40 cm) - 10 N (10 cm) + 30 N (30 cm) = 1400 N-cm
iii. No. The lever is not balanced in the situation. Because the moment is ± 1400 N-cm. if balance, the moment must be Zero.
iv. the location of 10N by keeping the other loads unchanged to balance the lever is 150 cm
take moment from Δ (support)
60(40) = 10(x) + 30(30)
2400 = 10x + 900
10x = 2400 - 900
10x = 1500
x = 1500/10
x = 150 cm
therefore, the location of 10N by keeping the other loads unchanged to balance the lever is 150 cm
Two identical balls are thrown directly upward, ball A at speed v and ball B at speed 2v, and they feel no air resistance. Which statement about these balls is correct
Answer:
B) Ball B will go four times as high as ball A because it had four times the initial kinetic energy.
Explanation:
The complete question is
Two identical balls are thrown directly upward, ball A at speed v and boll B at speed 2v. and they feel no air resistance. Which statement about these balls is correct? A) Ball B will go twice as high as ball A because it had twice the initial speed. B) Ball B will go four times as high as ball A because it had four times the initial kinetic energy. C) The balls will reach the same height because they have the same mass and the same acceleration. D) At its highest point, ball B will have twice as much gravitational potential energy as ball A because it started out moving twice as fast. E) At their highest point, the acceleration of each ball is instantaneously equal to zero because they stop for an instant.
According to conservation of energy, the mechanical energy of a ball thrown up is equal to the sum of the potential energy and the kinetic energy. At its highest point, all the mechanical energy will be equal to the potential energy. At the instant when it was thrown, all the mechanical energy is proportional to its kinetic energy, which will be proportional to the potential energy at the highest point. Also, potential energy is proportional to the maximum height reached.
We know that the kinetic energy is given as [tex]\frac{1}{2}mv^{2}[/tex]
where
m is the mass of the balls, which is the same for both ball,
and v is the velocity.
We can see that the kinetic energy is proportional to the square of the initial velocity with which the ball is thrown.
For the ball A thrown with velocity v, the kinetic energy is proportional to [tex]v^{2}[/tex],
and for the ball B with velocity 2v, kinetic energy is proportional to [tex]4v^{2}[/tex]
comparing the two, we'll see that the ball B will had 4 times the energy of ball A. Therefore ball B will go four times as high as ball A because it had four times the initial kinetic energy
An air-filled capacitor consists of two parallel plates, each with an area of 8 cm^2 , separated by a distance 2.9 mm. A 22 V potential difference is applied to these plates.
What is the magnitude of the surface charge density on each plate?
Answer:
The magnitude of the surface charge density on each plate is 6.714 x 10⁻⁸ C/m²
Explanation:
Given;
area of the parallel plates, A = 8 cm² = 8 x 10⁻⁴ m²
distance between the plates, d = 2.9 mm = 0.0029 m
potential difference applied to the plates, V = 22 V
The electric field between the plates is given by;
[tex]E = \frac{V}{d} \\\\E = \frac{22}{2.9*10^{-3}}\\\\E = 7586.207 \ V/m[/tex]
The surface charge density is given by;
σ = ε₀E
σ = (8.85 x 10⁻¹²)(7586.207)
σ = 6.714 x 10⁻⁸ C/m²
Therefore, the magnitude of the surface charge density on each plate is 6.714 x 10⁻⁸ C/m²
A bar of silicon is 4 cm long with a circular cross section. If the resistance of the bar is 280 Ω at room temperature, what is the cross-sectional radius of the bar?
Answer:
r = 17.05 cm
Explanation:
Given that,
Length of silicon bar is 4 cm or 0.04 m
Resistance of the bar is 280 ohms
We know that the resistivity of the silicon is 640 Ωm
We need to find the cross-sectional radius of the bar. Let it is r.
Using definition of resistance of an object. It is given by :
[tex]R=\rho\dfrac{l}{A}[/tex]
A is area of bar, A = πr²
So,
[tex]R=\rho\dfrac{l}{\pi r^2}\\\\r^2=\dfrac{\rho l}{R\pi}\\\\r^2=\dfrac{640\times 0.04}{280\pi}\\\\r=0.1705\ m\\\\r=17.05\ cm[/tex]
So, the cross-sectional radius of the bar is 17.05 cm.