Answer:
a
Explanation:
A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the radiation intensity at a distance of 2.00 m from the light bulb
so i did 60(50%)=30÷2=15
The radiation intensity is 15 W / m².
To find the radiation intensity, the values are given as,
Power = 60 W
Distance = 2 m
50% of the power input is emitted as electromagnetic radiation.
What is radiation intensity?The amount of energy emitted per unit solid angle by per unit area of the radiating surface can be said as radiation intensity.
As, when there is a power output, the input power will emit some energy as a kinetic energy and electromagnetic radiation. By the way, the power input emits 50 % as a radiation, so the power input given as,
P = 60 / 2 ( As it was 50 % )
= 30 Watt.
The radiation intensity is,
In = 30 / 2
= 15 W / m².
Thus, the radiation intensity is calculated as, 15 W/ m².
So, Option A is the correct answer.
Learn more about radiation intensity,
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An experiment consists of throwing balls straight up with varying initial velocities. Which quantity will have the same value in all trials?a) initial momentum.
b) maximum height.
c) time of travel.
d) acceleration.
Answer:
the correct answer is D, acceleration of gravity
Explanation:
In a projectile launch problem it is described by the expressions
v = v₀ - g t
v² = v₀² - 2 g y
y = v₀ t - ½ g t²
By examining these equations we can see that acceleration is the magnitude that appears constant in all expressions.
This acceleration is the acceleration of gravity with a value of g = 9.8 m/s² and directed towards the center of the Earth
therefore the correct answer is D
Which of the following phrases describes a motor?
A. Changes electrical energy to mechanical energy
B. Never used in appliances with moving parts
C. Can be powered by a hand crank
D. Does not use the interaction between a spinning coil of wire and a
magnet
For a research project, a student needs a solenoid that produces an interior magnetic field of 0.0300 T. She decides to use a current of 1.00 A and a wire 0.500 mm in diameter. She winds the solenoid in layers on an insulating form 1.00 cm in diameter and 10.0 cm long. Determine the number of layers of wire needed. (Round your answer up to the nearest integer.)
Answer:
121m
Explanation:
Magnetic field = 0.03
Current = 1.00A
Diameter = 0.5
Length = 10vm
B = UoIN/Lcylinder * n
n = number of layer
n = 0.5x10^-3 x 0.03/4pi x 10^-7 x 1
= 0.0005x0.03/12.56x10^-7
= 11.94
~12
Average radius
= 0.008
Length of wire = 2x3.13x0.008x12x200
= 120.6m
= 121m
During heavy lifting, a disk between spinal vertebrae is subjected to a 5000-N compressional force. (a) What pressure is created, assuming that the disk has a uniform circular cross section 2.00 cm in radius? (b) What deformation is produced if the disk is 0.800 cm thick and has a Young's modulus of 1.5×109 N/m2?
Answer:
[tex]3978873.58\ \text{Pa}[/tex]
[tex]0.00002122\ \text{m}[/tex]
Explanation:
F = Force = 5000 N
r = Radius of circular cross section = 2 cm
l = Length of disk = 0.8 cm
A = Area = [tex]\pi r^2[/tex]
Y = Young's modulus = [tex]1.5\times 10^9\ \text{N/m}^2[/tex]
Pressure is given by
[tex]P=\dfrac{F}{A}\\\Rightarrow P=\dfrac{5000}{\pi (2\times 10^{-2})^2}\\\Rightarrow P=3978873.58\ \text{Pa}[/tex]
The pressure on the cross section is [tex]3978873.58\ \text{Pa}[/tex]
The change in length of the cross section is given by
[tex]\Delta L=\dfrac{PL}{Y}\\\Rightarrow \Delta L=\dfrac{3978873.58\times 0.8\times 10^{-2}}{1.5\times 10^9}\\\Rightarrow \Delta L=0.00002122\ \text{m}[/tex]
The deformation produced is [tex]0.00002122\ \text{m}[/tex]
A stereo speaker is placed between two observers who are 35 m apart, along the line connecting them. If one observer records an intensity level of 64 dB, and the other records an intensity level of 85 dB, how far is the speaker from each observer
Answer:
x = 2,864 m , Ra = 32.1 m
Explanation:
Let's solve this problem in parts, let's start by finding the intensity of the sound in each observer
observer A β = 64 db
β = 10 log Iₐ / I₀
where I₀ = 1 10⁻¹² W / m²
Iₐ = I₀ 10 (β/ 10)
let's calculate
Iₐ = 1 10⁻¹² (64/10)
Iₐ = 2.51 10⁻⁶ W / m²
Observer B β = 85 db
I_b = 1 10-12 10 (85/10)
I_b = 3.16 10⁻⁴ W / m²
now we use that the emitted power that is constant is the intensity over the area of the sphere where the sound is distributed
P = I A
therefore for the two observers
P = Ia Aa = Ib Ab
the area of a sphere is
A = 4π R²
we substitute
Ia 4pi Ra2 = Ib 4pi Rb2
Ia Ra2 = Ib Rb2
Let us call the distance from the observer be to the haughty R = ax, so the distance from the observer A to the haughty is R = 35 ax; we substitute
Ia (35 -x) 2 = Ib x2
we develop and solve
35-x = Ra (Ib / Ia) x
35 = [Ra (Ib / Ia) +1] x
x (11.22 +1) = 35
x = 35 / 12.22
x = 2,864 m
This is the distance of observer B
The distance from observer A
Ra = 35 - x
Ra = 35 - 2,864
Ra = 32.1 m
Can someone help me with this question
Answer:
Net force: 20 N to the right
mass of the bag: 20.489 kg
acceleration: 0.976 m/s^2
Explanation:
Since the normal force and the weight are equal in magnitude but opposite in direction, they add up to zero in the vertical direction. In the horizontal direction, the 195 N tension to the right minus the 175 force of friction to the left render a net force towards the right of magnitude:
195 N - 175 N = 20 N
So net force on the bag is 20 N to the right.
The mass of the bag can be found using the value of the weight force: 201 N:
mass = Weight/g = 201 / 9.81 = 20.489 kg
and the acceleration of the bag can be found as the net force divided by the mass we just found:
acceleration = 20 N / 20.489 kg = 0.976 m/s^2
g A ping pong ball (thin shell sphere) rolls down an incline at 30° from rest. What is its acceleration
Answer:
Explanation:
According to newtons second law of motion;
F = ma .... 1
Also the force acting aong the inclines is expressed as;
F = mgsintheta
m is the mass of the object
a is the acceleration
theta is angle of inclination
Equate 1 and 2
ma = mg sin theta
a = gsin(theta)
a = 9.8sin30
a = 9.8(0.5)
a = 4.9m/s²
Hence the acceleration of the ping pong is 4.9m/s²
when you stir a cup of tea the floating clip collect at the centre of the Cup rather than in the outer Rim why
Answer:
hsvshxansjusjsnwjwisks
Explanation:
When we stir a cup of tea we create a force in the center which pulls out all the particles towards it this is the basic reason for collection of tea leaves at the center of the cup rather than at the rim of the cup, it is similar to the the case of tornado where it takes all the particles present on it way to its ..
A 5kg rock is lifted 2m. Find the amount of work done.
Answer:
98J
Explanation:
Given parameters:
Mass of rock = 5kg
Height = 2m
Unknown:
Work done = ?
Solution:
The amount of work done is given as:
Work done = Force x distance
Work done = Weight x height
Work done = mgH
Now insert the parameters and solve;
Work done = 5 x 9.8 x 2 = 98J
The amount of work done on the rock is equal to 98 Nm.
Given the following data:
Mass of rock = 5 kgDistance = 2 metersTo determine the amount of work done:
First of all, we would calculate the force acting on the rock:
[tex]Force = mg\\\\Force = 5 \times 9.8[/tex]
Force = 49 Newton
Now, we can determine the amount of work done:
[tex]Work \;done = force \times distance\\\\Work \;done = 49 \times 2[/tex]
Work done = 98 Nm
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A uniform electric field has a magnitude of 10 N/C and is directed upward. A charge brought into the field experiences a force of 50 N downward. The charge must be:_______.
Answer:
q = 5 C
Explanation:
The electric field is defined as the force experienced by a unit charge when it is brought into the field. Hence, the formula used to find the electrical field is given as follows:
E = F/q
where,
E = Electric Field Magnitude = 10 N/C
F = Force Experienced by the test charge = 50 N
q = Magnitude of the Charge = ?
Therefore,
10 N/C = 50 N/q
q = 50 N/(10 N/C)
Therefore,
q = 5 C
What voltage is required to move 6A through 5Ω?
A plane moves at a speed of 100 mi/h and takes flight on a 25 degree angle. What is the VERTICAL speed in mi/h? Round to the nearest whole number and DO NOT include units (Ex: 11).
Answer:
The vertical speed in mi/h is 42.
Explanation:
Rectangular Components of a Vector
A 2D vector can be expressed in several forms. The rectangular form gives its two components, one for each axis (x,y). The polar form gives the components as (r,θ) being r the magnitude and θ the angle.
The relationships between the coordinates of both systems are shown in the image below.
When the magnitude and angle of the vector are given, the rectangular components are calculated as follows:
[tex]v_x=v\cos\theta[/tex]
[tex]v_y=v\sin\theta[/tex]
Where v is the magnitude of the vector and θ is the angle with respect to the x positive direction.
We are given the magnitude of the velocity (the speed) at which a plane is moving as v=100 mi/h at an angle of θ=25°, the vertical component of the velocity is:
[tex]v_y=100\sin 25^\circ[/tex]
Calculating:
[tex]v_y=42.26\approx 42[/tex]
The vertical speed in mi/h is 42.
You can chew through very tough objects with your incisors because they exert a large force on the small area of a pointed tooth. What pressure in pascals can you create by exerting a force of 500 N with your tooth on an area of 1.00 mm?
Answer:
sry i need points
Explanation:
A rope is wrapped around the rim of a large uniform solid disk of mass 325 kg and radius 3.00 m. The horizontal disk is made to rotate by pulling on the rope with a constant force of 195 N. If the disk starts from rest, what is its angular speed in rev/s at the end of 2.05 s?
Answer:
The angular speed is 0.13 rev/s
Explanation:
From the formula
[tex]\tau = I\alpha[/tex]
Where [tex]\tau[/tex] is the torque
[tex]I[/tex] is the moment of inertia
[tex]\alpha[/tex] is the angular acceleration
But, the angular acceleration is given by
[tex]\alpha = \frac{\omega}{t}[/tex]
Where [tex]\omega[/tex] is the angular speed
and [tex]t[/tex] is time
Then, we can write that
[tex]\tau = \frac{I\omega}{t}[/tex]
Hence,
[tex]\omega = \frac{\tau t}{I}[/tex]
Now, to determine the angular speed, we first determine the Torque [tex]\tau[/tex] and the moment of inertia [tex]I[/tex].
Here, The torque is given by,
[tex]\tau = rF[/tex]
Where r is the radius
and F is the force
From the question
r = 3.00 m
F = 195 N
∴ [tex]\tau = 3.00 \times 195[/tex]
[tex]\tau = 585[/tex] Nm
For the moment of inertia,
The moment of inertia of the solid disk is given by
[tex]I = \frac{1}{2}MR^{2}[/tex]
Where M is the mass and
R is the radius
∴[tex]I = \frac{1}{2} \times 325 \times (3.00)^{2}[/tex]
[tex]I = 1462.5[/tex] kgm²
From the question, time t = 2.05 s.
Putting the values into the equation,
[tex]\omega = \frac{\tau t}{I}[/tex]
[tex]\omega = \frac{585 \times 2.05}{1462.5}[/tex]
[tex]\omega = 0.82[/tex] rad/s
Now, we will convert from rad/s to rev/s. To do that, we will divide our answer by 2π
0.82 rad/s = 0.82/2π rev/s
= 0.13 rev/s
Hence, the angular speed is 0.13 rev/s,
How are graphs used to represent and analyze acceleration? please help!
A 0.22 caliber handgun fires a 1.9g bullet at a velocity of 765m/s. Calculate the de Broglie wavelength of the bullet. Is the wave nature of matter significant for the bullets?
Answer:
de Broglie wavelength of the bullet is 4.56 x 10⁻³⁴ mThe value of the wavelength shows that wave nature of matter is insignificant for the bullet because it is larger than particles.Explanation:
Given;
mass of the bullet, m = 1.9 g = 0.0019 kg
velocity of the bullet, v = 765 m/s
de Broglie wavelength of the bullet is given by;
[tex]\lambda = \frac{h}{mv}[/tex]
where;
h is Planck's constant = 6.626 x 10⁻³⁴ J/s
λ is de Broglie wavelength of the bullet
[tex]\lambda = \frac{h}{mv}\\\\ \lambda =\frac{(6.626*10^{-34})}{(0.0019)(765)}\\\\ \lambda =4.56 *10^{-34} \ m[/tex]
Thus, this value of the wavelength shows that wave nature of matter is insignificant for the bullet because it is larger than particles.
Given:
Mass, m = 1.9 g or, 0.0019 kgVelocity, v = 765 mPlank's constant, h = 6.626 × 10⁻³⁴ J/sThe De-Broglie wavelength,
→ [tex]\lambda = \frac{h}{mv}[/tex]
By putting the values,
[tex]= \frac{6.626\times 10^{-34}}{0.0019\times 765}[/tex]
[tex]= 4.56\times 10^{-34} \ m[/tex]
Thus the response above is right.
Learn more about wavelength here:
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A light truck with manual transmission has a circular brake drum with a diameter of d = 310 millimeters. Each brake pad, which presses against the drum, is s = 306 millimeters long. What central angle is subtended by one of the brake pads? Write your answer in both radians and degrees.
Answer:
113 degrees
1.974 radians
Explanation:
The angle can be calculated using below expression
Angle = arc/r
Where arc= diameter of d = 310 millimeters
r= s = 306 millimeters long.
Since both have the same unit, no need for conversion
Angle = arc/r = 306/(0.5×310 )
= 306/155
= 1.974 radians
Then to find the angle In degrees we have
R x 180/pi = D
Where R= angle in radians= 1.974 radians
1.974 x 180/π
Where π= 22/7
= 113 degrees( approximately)
Therefore, central angle is subtended by one of the brake pads is 1.974 radians
It has been suggested that rotating cylinders about 12.5 mi long and 6.25 mi in diameter be placed in space and used as colonies. What angular speed must such a cylinder have so that the centripetal acceleration at its surface equals the free-fall acceleration on Earth?
Answer:
w = 0.0436 rad/s
Explanation:
Radius of the cylinder is
3.125 * 1609m/mile = 5028 m
Using the angular acceleration formula, we have
a = v²/r = w²r.
Since we're interested in the angular speed, we make w the subject of the formula, so that
w² = a/r
w = √a/r
w = √(9.8/5028)
W = √0.0019049
w = 0.0436 rad/s
Then we can conclude that the angular speed of the rotation is w = 0.0436 rad/s
If a penny is dropped from rest from a tower takes 2 seconds to hit the ground, how far did it travel?
a 29.4 m
b 19.6 m
с 6.8 m
d 9.8 m
Answer:
B
Explanation:
t = 2s
u = 0m/s (released from rest)
a = +g = 9.8m/s²
s = H = ?
using,
s = ut + 1/2at²
H = 0(2) + 1/2(9.8)(2²)
H = 0 + 9.8(2)
s = H = 19.6m
What is the picture called that shows ALL the forces acting on an object?
Answer:
Free Body Diagram
Explanation:
Such picture is called the "free body diagram"
How does cycling of matter occur in Earth’s mantle?
A. Hot, soft rock rises from the bottom of the mantle toward the top, cools, and sinks back through the mantle.
B. Hot, soft rock sinks to the mantle, cools, and rises to Earth’s crust.
C. Solid rock rises from the bottom of the mantle, cools, and sinks back through the mantle.
D. Solid rock sinks to Earth’s core and then rises to form lava.
i need help fast plz and thank you
11/24/2020
Answer:
Correct answer to this is: A
Hopefully, this helped out a bit :)
If it requires 7.0 J of work to stretch a particular spring by 1.8 cm from its equilibrium length, how much more work will be required to stretch it an additional 3.6 cm?
Answer:
56 J
Explanation:
The following data were obtained from the question:
Energy 1 (E₁) = 7 J
Extention 1 (e₁) = 1.8 cm
Extention 2 (e₂) = 1.8 + 3.6 = 5.4 cm
Energy 2 (E₂) =?
Energy stored in a spring is given by the following equation:
E = ke²
Where E is the energy.
K is the spring constant.
e is the extension.
E = ke²
Divide both side by e²
K = E/e²
Thus,
E₁/e₁² = E₂/e₂²
7/ 1.8² = E₂/ 5.4²
7 / 3.24 = E₂/ 29.16
Cross multiply
3.24 × E₂ = 7 × 29.16
3.24 × E₂ = 204.12
Divide both side by 3.24
E₂ = 204.12 / 3.24
E₂ = 63 J
Thus, the additional energy required can be obtained as follow:
Energy 1 (E₁) = 7 J
Energy 2 (E₂) = 63 J
Additional energy = 63 – 7
Additional energy = 56 J
Which of the following locations will be relatively warmer during summers, and why? A. An inland location, because water heats up faster than land.
B. A coastal location, because water heats up faster than land.
C. A coastal location, because water has higher specific heat than land.
D. An inland location, because land has lower specific heat than water.
This is a short question can anyone help me please
Thank you
Picture Above
Answer:
I thinks it's
deficit spending
Explanation:
cause When a government spends more than it collects in taxes, it is said to have a budget deficit.
A guitar string produces 3 beats/s when sounded with a 352 Hz tuning fork and 8 beat/s when sounded with a 357 Hz tuning fork. What is the vibrational frequency (in Hz) of the string
Answer:
349 Hz
Explanation:
We are told that the guitar string produces 3 beats/s when sounded with a 352 Hz tuning fork and 8 beat/s when sounded with a 357 Hz tuning fork.
This means that for the 352 Hz tuning fork, the vibrational frequency is;
f = 352 ± 3
f = (352 + 3) or (352 - 3)
f = 355 Hz or 349Hz
For the 357 Hz tuning fork, the vibrational frequency is;
f = 357 ± 8
f = (357 + 8) or (357 - 8)
f = 365 Hz or 349 Hz
In both cases, 349 Hz is common;
Thus, the vibrational frequency of the string = 349 Hz
A boxer is punching the heavy bag. The impact of the glove with the bag is 0.10s. The mass of the glove and his hand is 3kg. The velocity of the glove just before impact is 25m/s. What is the average impact force exerted on the glove?
Answer:
750NExplanation:
Impulse is the change of momentum of an object when the object is acted upon by a force for an interval of time.
the expression is Ft=mv
where F= force
m= mass
t= time
v= velocity
Step one:
given data
mass m=3kg
velocity v= 25m/s
time t= 0.10seconds
Step two:
we also know that the force on impulse is given as
Ft=mv
F=3*25/0.10
F=75/0.10
F=750N
The magnitude of the average force on the heavy bag if the duration of the collision is 0.1 is 750N
A falling ball has potential energy of 5 J and a kinetic energy of 10 J. What is the ball's mechanical energy?
How long does it take a vehicle to reach a velocity of 32 m/s if it accelerates from rest at a rate of 4.2 m/s^2?
What is the initial velocity of the vehicle?
What is the final velocity of the vehicle?
What is the acceleration of the vehicle?
Write the equation you will use to solve the problem.
How long does it take the vehicle to reach its final velocity?
0.13 seconds
18.1 seconds
7.62 seconds
134.4 seconds
Answer:
7.62
Explanation:
because you have to divide 32/4.2
and can you do a friend request so i can accept it
Any five physics problems
Explanation:
There are still some questions beyond the Standard Model of physics, such as the strong CP problem, neutrino mass, matter–antimatter asymmetry, and the nature of dark matter and dark energy.
A football player runs down the field at a speed of 8 m/s how long will it take him to run 20 m?