Answer:
Intensity at 12 meters will be 11.11 W/m^2
Explanation:
Recall that the intensity of sound is inversely proportional to the square of the distance from the source. Therefore, if at 4 m the intensity is 100 W/m^2
we have: 100 W/m^2 = k/16 and therefore, k = 1600 W
Then the intensity (I) at 12 m will be:
I = k/12^2 = 1600/144 W/m^2 = 11.11 W/m^2
Mr Johnson launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, how much time does it take before the arrow hits the ground below (step 1 of a quesiton will need this answer for a future question)
a 2 seconds
b. 1 second
c.4 seconds
d 19.6
Answer:c
Explanation:
Sam heats an 8kg sample of sand, with a specific heat of 664 J/kg·C°, from 20° to 40°. What is the change in thermal energy?
Answer:
106.24 kJ.
Explanation:
Given that,
Mass of sample of sand, m = 8 kg
Specific heat of sand, c = 664 J/kg-°C
The temperature changes from 20° C to 40° C. We need to find the change in thermal energy. It is given by :
[tex]Q=mc\Delta T\\\\Q=8\times 664(40-20)\\\\=106240\ J\\\\=106.24\ kJ[/tex]
So, the change in thermal energy is 106.24 kJ.
Which of the following requires the expenditure of more work?
a. Lifting a 110 newton [N] weight a height of 3 meters [m].
b. Exerting a force of 60 pounds-force [lbf] on a sofa to slide it 30 feet [ft] across a room.
Answer:
The correct answer is option B
Explanation:
Step one:
given data
a. force F= 110N
distance s= 3meters
we know that work= Force* distance
work= 110*3
Work= 330Joules
Step two:
data
Force= 60 pounds
distance= 30 ft
convert pounds to Newton
1 pound= 4.44822N
60 pounds= 60*4.44822
=266.9N
convert ft to meteres
1 ft = 0.3048meter
30ft= 0.3048*30
=9.144N
we know that work= Force* distance
work= 266.9N*9.144N
Work= 2440.53Joules
Please help, I'm really struggling here, I can't do science :(
The mass of Jupiter is about 320 times the mass of Earth. However, Jupiter’s gravity affects Earth very little because_____________. a Earth is so far from Jupiter. b Earth is so small. c Jupiter is made of gas. d Jupiter is nearer to the sun than Earth is.
Answer:no sure sorry
Explanation:
which thermometer is used in hot region.why?
Answer:
Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion.
Explanation:
please mark me brainlist
Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion. they still use mercury even though it is the poorest conductor of heat.
Which possible component of initial energy is caused by molecular motion within a material?
Answer: thermal energy
Answer:
Thermal energy
Explanation:
The internal energy of a system is widely known as thermal energy. Now, thermal energy is also called heat energy and it is an internal energy of a component which is produced when an increase in temperature causes atoms and molecules within the component to move faster and start colliding with one other.
Therefore, the more heat the is applied to the component, the hotter the substance and the more its particles move which in turn leads to a higher thermal energy.
A typical elevator car with people has a mass of 1500.0 kg. Elevators are currently approaching speeds of 20.0 m/s - faster than the speed.
Required:
What is the upward force required if the elevator moves upward 200.0 meters before reaching 20.0 m/s?
Answer:
1500NExplanation:
Force = mass * acceleration
Given
Mass = 1500kg
Get the acceleration using the equation of motion;
v² = u²+2aS
20² = 0+2s(200)
400 = 400a
a = 400/400
a = 1m/s²
Get the upward force required
F = 1500 * 1
F = 1500N
Hence the upward force required if the elevator moves upward 200.0 meters before reaching 20.0 m/s is 1500N
A wire of radius 0.8 cm carries a current of 106 A that is uniformly distributed over its cross-sectional area. Find the magnetic field B at a distance of 0.07 cm from the center of the wire.
Answer:
The magnetic field is [tex]B = 2.319 *10^{-3} \ T[/tex]
Explanation:
From the question we are told that
The radius of the wire is [tex]r = 0.8 \ cm = 0.008 \ m[/tex]
The current is [tex]I = 106 \ A[/tex]
The position considered is d = 0.07 cm = 0.0007 m
Generally the magnetic field is mathematically represented as
[tex]B = \frac{\mu_o * I}{2\pi * \frac{r^2}{d} }[/tex]
Here [tex]\mu_o[/tex] is the permeability of free space with value [tex] 4\pi * 10^{-7} N/A^2[/tex]
So
[tex]B = \frac{ 4\pi * 10^{-7} * 106 }{2 * 3.142 * \frac{0.008^2}{0.0007} }[/tex]
=> [tex]B = 2.319 *10^{-3} \ T[/tex]
1. Opposite charges
O repel
attract
Answer:
attract
Explanation:
that is the answer
Answer:
Attract.
Explanation:
I took the quiz.
giving brainliest to first one who gets this right
a. Nitrogen, Oxygen,and Carbon Dioxide
hope im right but I dont really know
At an air show a jet flies at speed 1500 km/h on a day when the speed of sound is 342 m/s. What is the angle of the shock cone
Answer:
55 degrees
Explanation:
Given that an air show a jet flies at speed 1500 km/h on a day when the speed of sound is 342 m/s.
From the question above, we can get the below parameters
Object speed (V) = 1500 km/h
Sound speed ( v) = 342 m/s
Convert km/h to m/s
(1500 × 1000)/3600
Jet speed V = 416.67 m/s
Let's first calculate the mash number M.
M = V/v
M = 416.67 / 342
M = 1.2183
Formula for the angle of the shock cone is reciprocal of mash number. That is,
Sin Ø = 1 / M
Sin Ø = 1 / 1.2183
Sin Ø = 0.8208
Ø = sin^-1(0.8208)
Ø = 55 degree
Therefore, the angle of the shock cone is approximately 55 degrees
10points asap
A force of 30 N acts upon a 7 kg block. Calculate its acceleration.
Two parallel 3.0-meter long wires conduct current. The current in the top wire is 12.5 A and flows to the right. The top wire feels a repulsive force of 2.4 x 10^-4 N created by the interaction of the 12.5 A current and the magnetic field created by the bottom current (I). Find the magnitude and direction of the bottom current.
Complete question:
Two parallel 3.0-meter long wires conduct current. The current in the top wire is 12.5 A and flows to the right. The top wire feels a repulsive force of 2.4 x 10^-4 N created by the interaction of the 12.5 A current and the magnetic field created by the bottom current (I). Find the magnitude and direction of the bottom current, if the distance between the two wires is 40cm.
Answer:
The bottom current is 12.8 A to the right.
Explanation:
Given;
length of the wires, L = 3.0 m
current in the top wire, I₁ = 12.5 A
repulsive force between the two wires, F = 2.4 x 10⁻⁴ N
distance between the two wires, r = 40 cm = 0.4 m
The repulsive force between the two wires is given by;
[tex]F = \frac{\mu_oI_1I_2L}{2\pi r}\\\\I_{2} = \frac{2F\pi r}{\mu_oI_1L}[/tex]
Where;
I₂ is the bottom current
The direction of the bottom current must be in the same direction as the top current since the force between the two wires is repulsive.
[tex]I_{2} = \frac{2F\pi r}{\mu_oI_1L}\\\\I_{2} = \frac{2(2.4*10^{-4})(\pi)(0.4)}{(4\pi*10^{-7})(12.5)(3)}\\\\I_{2} = 12.8 \ A[/tex]
Therefore, the bottom current is 12.8 A to the right.
A football player runs down the field at a speed of 8 m/s how long will it take him to run 20 m?
Your teacher placed a 3.5 kg block at the position marked with a “ + ” (horizontally, 0.5 m from the origin) on a large incline outlined on the graph below and let it slide, starting from rest. ***There are two images included!***
Answer:
x = 10.75 m
Explanation:
For this problem we will solve it in two parts, the first using energy and the second with kinematics
Let's use the energy work relationship to find the velocity of the block as it exits the ramp
W = [tex]Em_{f}[/tex] - Em₀
Starting point. Higher
Em₀ = U = m g h
the height from the edge of the ramp of the graph has a value
h = 9-3 = 6 m
Final point. At the bottom of the ramp
Em_{f} = K = ½ m v²
Friction force work
W = - fr d
The friction force has the formula
fr = μ N
On the ramp, we can use Newton's second law
N - W cos θ = 0
N = W cos θ
where the angle is obtained from the graph
tan θ = (9-3) / (0.5-4) = -6 / 3.5
θ = tan⁻¹ (-1,714)
θ = -59.7º
the distance d is
d = √ (Δx² + Δy²)
d = √ [(0.5-4)² + (9-3)²]
d = 6.95 m
for which the work is
W = - μ mg cos 59.7 d
we substitute
W = Em_{f} -Em₀
- μ mg cos 59.7 d = ½ m v² - m g h
In the graph o text the value of the friction coefficient is not observed, suppose that it is μvery = 0.2
- μ g cos 59.7 d = ½ v² - g h
v² = 2g (h - very d coss 59.7)
let's calculate
v² = 2 9.8 (6 - 0.2 6.95 cos 59.7)
v = √ 103.8546
v = 10.19 m / s
in the same direction as the ramp
in the second part we use projectile launch kinematics
let's look for the components of velocity
v₀ₓ = vo cos -59.7
[tex]v_{oy}[/tex] = vo sin (-59,7)
v₀ₓ = 10.19 cos (-59.7) = 5.14 m / s
v_{oy} = 10.19 if (-59.7) = -8.798 m / s
Let's find the time to get to the floor (y = o)
y = y₀ + v_{oy} t - ½ g t²
to de groph y₀=3 m
0 = 3 - 8.798 t - ½ 9.8 t²
t² - 1.796 t - 0.612 = 0
we solve the quadratic equation
t = [1.796 ±√(1.796² + 4 0.612)] / 2
t = [1,795 ± 2,382] / 2
t₁ = 2.09 s
t₂ = -0.29 s
since time must be a positive quantity the correct value is t = 2.09 s
we calculate the horizontal displacement
x = v₀ₓ t
x = 5.14 2.09
x = 10.75 m
The motion of the box, after it exits the incline is the motion and trajectory
of a projectile.
Horizontal distance from the right-hand edge of the incline to the point of
contact with the floor is approximately 1.24613 m.
Reasons:
Mass of the block, m = 3.5 kg
Coefficient of kinetic friction, μ = 1.2
Location of the = 0.5 m from the origin
Required:
Horizontal distance between the block's point of contact with the floor and
the bottom right-hand edge of the incline.
Solution:
Let θ represent the angle the incline make with the horizontal.
The normal reaction of the incline on the block, [tex]F_N[/tex] = m·g·cos(θ)
Work done on friction = [tex]F_N[/tex]×μ×Length of the incline, L
Rise of the incline = 10 - 3 = 7
Run of the incline = 4
L = √(6.125² + 3.5²) = [tex]\dfrac{7 \times \sqrt{65} }{8}[/tex]
Let ΔP.E.₁ represent the potential energy transferred to kinetic energy
and work along the incline, we have;
Energy of the block at the bottom of the incline, M.E.₂, is found as follows;
K.E.₂ = mgh - m·g·μ·cos(θ)·L
[tex]K.E. =\frac{1}{2} \times 3.5 \times v^2 = 3.5 \times 9.81 \times 6.125 - 3.5 \times 9.81 \times 1.2 \times \dfrac{4}{\sqrt{65} } \times \dfrac{7 \times \sqrt{65} }{8}[/tex]
v ≈ 6.1456 m/s
The vertical component of the velocity is therefore;
[tex]v_y = v \cdot sin(\theta)[/tex]
[tex]v_y = 6.1456 \times \dfrac{7}{\sqrt{65} } \approx 5.33588[/tex]
From the equation, h = u·t + 0.5·g·t² derived from Newton's Laws of motion, we have;
ΔP.E.₁ = 3.5×9.81×7
3 = 5.33588·t + 0.5×9.81·t²
Factorizing, the above quadratic equation, we get;
The time it takes the block to reach the floor, t ≈ 0.40869 seconds
Horizontal component of the velocity is [tex]v_x \approx 6.1456 \times \dfrac{4}{\sqrt{65} } \approx 3.04908[/tex]
The horizontal distance, x = vₓ × t
∴ x = 3.04908 × 0.40869 ≈ 1.08194
Horizontal distance from the right-hand edge of the incline to the point of
contact with the floor, x ≈ 1.24613 m.
Learn more here:
https://brainly.com/question/24888457
A 45 kg object has a momentum of 225 kg-m/s northward. What is the object's velocity?
A. 180 m/s
B. 5.0 m/s
C. 10,125 m/s
D. 0.20 m/s
A displacement vector with a magnitude of 20. meters could have perpendicular components with magnitudes of A. 10. m and 10. m B. 12 m and 8.0 m 12 m and 16 m D. 16 m and 8.0 m
Answer:10.m and 10. M
Explanation:
A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.
A displacement vector with a magnitude of 20. meters can be decomposed in 2 perpendicular components.
They would form a right triangle, in which the displacement vector would be the hypotenuse (a) and the components would be the legs (b, c).
Given the magnitude of the legs, we can calculate the magnitude of the hypotenuse using the Pythagorean theorem.
[tex]c = \sqrt{a^{2} + b^{2} }[/tex]
Let's use this formula to calculate the displacement vector for each pair of legs.
A. 10. m and 10. m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(10.m)^{2} + (10.m)^{2} }= 14.1m[/tex]
B. 12 m and 8.0 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (8.0m)^{2} }= 14.4m[/tex]
C. 12 m and 16 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (16m)^{2} }= 20m[/tex]
D. 16 m and 8.0 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(16m)^{2} + (8.0m)^{2} }= 17.9m[/tex]
A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.
Learn more: https://brainly.com/question/16426393
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 television of mass 15 kg sits on a table. The coefficient of static friction
between the table and the television is 0.35. What is the minimum applied
force that will cause the television to slide?
A) 38 N
B) 147 N
C) 51 N
D) 79 N
Answer:
more than 51.45 N
__________________________________________________________
We are given:
Mass of the television = 15 kg
Coefficient of Static friction = 0.35
Minimum force required to move the television:
Normal Force:
We know that the normal force is equal and opposite to the Weight of the television
Weight of the television = Mg
[where m is the mass and g is the acceleration due to gravity]
Weight = 15 * 9.8
Weight = 147 N
Force of Friction:
We are given the coefficient of Friction = 0.35
We know that coefficient of Friction = Force of friction / Normal Force
replacing the variables
0.35 = Force of Friction / 147
Force of Friction = 147 * 0.35 [multiplying both sides by 147]
Force of Friction = 51.45 N
Since a force of 51.45 N is will be applied opposite to the direction of application of Force, the television will only move when we apply more force than 51.45 N
Answer:
it is C
Explanation:
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
Answer:
why do you think the senate changed the way it voted? What methods did the suf
why do you think the senate changed the way it voted? What methods did the suffragis
why do you think the senate changed the way it voted? What methods did the suffragists use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolTwo manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?ts use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolfragists use to influence this change?
Explanation:
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hilol
A footballer kicks a ball from rest. The foot is in contact with the ball for 0.30s and the final velocity of the ball is 15ms-1 .What is the average acceleration of the ball?
Answer:
50m/s^2Explanation:
Step one:
given data
initial velocity u= 0m/s since the ball is at rest
time of contact t= 0.3s
final velocity v=15m/s
Required
acceleration a
from the first law of motion
v=u+at
substitute our given data
15=0+a*0.3
15=0.3a
divide both sides by 0.3
a=15/0.3
a=50m/s
The average acceleration is 50m/s^2
Answered: A 4 kg mass is attached to a horizontal spring with the spring constant of 600 N/m and rests on a frictionless surface on the ground. The spring is compressed 0.5 m past its equilibrium. What is the initial energy of the system.
Answer: 75 joules
WHAT IS TRANS ATLANTIC SLAVE TRADE
Find the change in thermal energy of a 25kg severed clown doll head that heats up from 25°C to 35°C, and has the specific heat of 1,700 J/(kg°C).
Answer:
Q = 425 kJ
Explanation:
Given that,
Mass, m = 25 kg
The clown doll head that heats up from 25°C to 35°C
The specific heat is 1700 J/kg°C
We need to find the internal energy of it. The heat required to raise the temperature is given by the formula as follows :
[tex]Q=mc\Delta T\\\\Q=25\times 1700\times (35-25)\\\\Q=425000\ J\\\\Q=425\ kJ[/tex]
So, 425 kJ of thermal energy is severed.
how long does the guided discovery stage of the drawing in phase last? in training program
Answer:
2 to 3 weeks
Explanation:
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 does a magnet induce an electric current in a wire coil?
O A. When the wire is connected to the coil
O B. When the magnet is near the coil
O C. When the magnet is moving back and forth in the coil
D. When the magnet is very strong
Answer:
B I believe
Explanation:
Select all correct answers....Covalent compounds
Which of these should you always do at the end of a calculation
Answer:
Reverse check the answer
Explanation:
I believe it is very important that once someone is done with any calculation, the person ought to go over the calculations again. And even, recheck the answer in inverted form.
This is so because while doing the calculations, we can possibly make errors that we won't notice until after submission. Knowing 2 * 3 = 6, but writing 2 * 3 = 5 in the course of calculations can happen to anybody. So therefore, cross checking and reverse checking is needed
what transition metal has 5 more protons than the halogen found in period 3?
Answer: Titanium (Ti)
Explanation:
First, each element has a unique atomic number Z, that is equal to the number of protons in the nucleus.
The halogen in period 3 is chlorine (Ch)
Chlorine's atomic number is Z = 17, this means that it has 17 protons.
Now we want to find a transition metal that has 5 more protons, then this transition metal has Z = 17 + 5 = 22
Now we can look at the periodic table and find the element with Z = 22, and if this is in the d-block, then this will be a transition metal.
The element with Z = 22 is titanium (Ti)