Answer:
22.87 m/s
Explanation:
Since the value of the height at which the divers jump off the cliff is not given,
Assuming that the height of the cliff above the ocean at which the divers jump = 26.7 m
Then;
The speed of the divers when they hit the ocean water can be determined by using the formula:
[tex]v^2 = 2gh \\ \\ v= \sqrt{2gh} \\ \\ v = \sqrt{2 \times 9.8 \times (26.7)} \\ \\ v \simeq 22.87 \ m /s[/tex]
two 100 ohm resistors are connected inparallel and one identical resister in series. The maximum power that can be delivered to any one resistor is 25W. What is the maximum voltage that can be applied between the terminals A and B ?
A. 50V
B. 75V
C. 100V
D. 125V
SOLVED DOWN BELOW
Explanation:
In series the same current goes thru both resistors, equiv resistance is 200 ohms, then using ohms law
I = 25/200
I= .125 amps or 125 ma
__________
R= r1 * r2 / r1 +r2
R= 100 * 100 / 100 + 100
R= 10000 / 200
R= 50 ohms
A parallel plate vacuum capacitor has 8.40 J of energy stored. The separation between plates is 2.30 mm. If the separation is decreased to 1.15 mm what is the energy stored if (a) the charge Q on the plates is held constant, and (b) the voltage V across the plates is held constant
(a) 4.20 J
(b) 16.74 J
Explanation:For a parallel plate vacuum capacitor with area A and whose plates are separated by by a distance of d, its capacitance C is given by;
C = A∈₀ / d --------------------(i)
Where;
∈₀ = constant called permittivity of vacuum.
The energy U stored in such capacitor is given by;
U = [tex]\frac{1}{2}[/tex]CV² ----------------------(ii)
or
U = [tex]\frac{1}{2}[/tex](Q²/C) -------------------(**)
Where;
V = potential difference or voltage across the plates.
Q = charge on the plates.
(a) If the charge is held constant
Combine equations (i) and (**) to give;
U = [tex]\frac{1}{2}[/tex]Q² / (A∈₀ / d) -----------------------(iii)
From the question;
The parallel plate capacitor has 8.40J energy stored and distance between plates is 2.30mm i.e
U = 8.40J
d = 2.30mm = 0.023m
Substitute these values into equation (iii)
8.40 = [tex]\frac{1}{2}[/tex]Q² / (A∈₀ / 0.023)
8.40 = [tex]\frac{1}{2}[/tex]Q² x (0.023 / A∈₀)
Multiply through by 2
2 x 8.40 = Q² x (0.023 / A∈₀)
16.80 = Q² x (0.023 / A∈₀)
Divide through by 0.023
16.80 / 0.023 = Q² x (0.023 / A∈₀) / 0.023
730.4 = Q² / (A∈₀)
Make Q² subject of the formula
Q² = 730.4(A∈₀)
Now, if the separation distance is decreased to 1.15mm and the voltage is held constant i.e
d = 1.15mm = 0.0115m
Q = constant [this means that Q² still remains 730.4(A∈₀) ]
The energy stored is found by substituting these values of d and Q² into equation (iii) as follows;
U = [tex]\frac{1}{2}[/tex]Q² / (A∈₀ / d)
U = [tex]\frac{1}{2}[/tex](730.4(A∈₀)) / (A∈₀ / 0.0115)
U = [tex]\frac{1}{2}[/tex](730.4(A∈₀))(0.0115 / A∈₀)
U = [tex]\frac{1}{2}[/tex](730.4)(0.0115)
U = 4.20J
Therefore, the energy stored if the charge Q on the plates is held constant is 4.20 J
(b) If the voltage is held constant
Combine equations (i) and (ii) to give;
U = [tex]\frac{1}{2}[/tex](A∈₀ / d)V² -----------------------(iv)
From the question;
The parallel plate capacitor has 8.40J energy stored and distance between plates is 2.30mm i.e
U = 8.40J
d = 2.30mm = 0.023m
Substitute these values into equation (iv)
8.40 = [tex]\frac{1}{2}[/tex](A∈₀ / 0.023)V²
Multiply through by 2 x 0.023
2 x 0.023 x 8.40 = (A∈₀)V²
2 x 0.023 x 8.40 = (A∈₀)V²
0.385 = (A∈₀)V²
Make V² subject of the formula
V² = 0.385/(A∈₀)
Now, if the separation distance is decreased to 1.15mm and the voltage is held constant i.e
d = 1.15mm = 0.0115m
V = constant [this means that V² still remains 0.385/(A∈₀) ]
The energy stored is found by substituting these values of d and V² into equation (iv) as follows;
U = [tex]\frac{1}{2}[/tex](A∈₀ / 0.0115)[0.385/(A∈₀)]
U = [tex]\frac{1}{2}[/tex](0.385/0.0115)
U = 16.74
Therefore, the energy stored if the voltage V across the plates is held constant is 16.74 J
One solenoid is centered inside another. The outer one has a length of 50.0 cm and contains 6750 coils, while the coaxial inner solenoid is 3.0 cm long and 0.120 cm in diameter and contains 15 coils. The current in the outer solenoid is changing at 49.2 A>s. (a) What is the mutual inductance of these solenoids
Answer: The mutual inductance of these solenoids is [tex]2.88 \times 10^{-7} H[/tex].
Explanation:
Given: Length = 50.0 cm (1 cm = 0.01 m) = 0.50 m
[tex]N_{1}[/tex] = 6750
[tex]N_{2}[/tex] = 15
Radius = [tex]\frac{0.120 cm}{2} = 0.6 cm = 6 \times 10^{-4} m[/tex]
As inner of a solenoid resembles the shape of a circle. So, its area is calculated as follows.
[tex]Area = \pi \times r^{2} = \pi \times (6 \times 10^{-4})^{2}[/tex]
Formula used to calculate mutual conductance of two solenoids is as follows.
[tex]M = \frac{\mu_{o} \times A \times N_{1} \times N_{2}}{l}[/tex]
where,
M = mutual conductance
A = area
[tex]\mu_{o}[/tex] = relative permeability = [tex]4 \pi \times 10^{-7} Tm/A[/tex]
[tex]N_{1}[/tex] = no. of coils in outer solenoid
[tex]N_{2}[/tex] = no. of coils in inner solenoid
l = length
Substitute the values into above formula as follows.
[tex]M = \frac{\mu_{o} \times A \times N_{1} \times N_{2}}{l}\\= \frac{4 \pi \times 10^{-7} Tm/A \times \pi (6 \times 10^{-4})^{2} \times 6750 \times 15}{0.5 m}\\= 2.88 \times 10^{-7} H[/tex]
Thus, we can conclude that the mutual inductance of these solenoids is [tex]2.88 \times 10^{-7} H[/tex].
Which of these is NOT an effect of humor?
strengthened immune system
reduced stress levels
reduced feelings of anxiety
feelings of jealousy and envy
As a new electrical engineer for the local power company, you are assigned the project of designing a generator of sinusoidal ac voltage with a maximum voltage of 120 V. Besides plenty of wire, you have two strong magnets that can produce a constant uniform magnetic field of 1.5 T over a square area with a length of 10.2 cm on a side when the magnets are separated by a distance of 12.8 cm . The basic design should consist of a square coil turning in the uniform magnetic field. To have an acceptable coil resistance, the coil can have at most 400 loops.
What is the minimum rotation rate of the coil so it will produce the required voltage? Express your answer using two significant figures.
Answer:
The rotation rate is 15.3 rad/s.
Explanation:
maximum voltage, V = 120 V
Magnetic field, B = 1.5 T
length, L = 10.2 cm
width, W = 12.8 cm
Number of loops, N = 400
Let the rate of rotation is w.
The maximum voltage is given by
V = N B A w
120 = 400 x 1.5 x 0.102 x 0.128 x w
w = 15.3 rad/s
an object moves clockwise around a circle centered at the origin with radius m beginning at the point (0,). a. find a position function r that describes the motion of the object moves with a constant speed, completing 1 lap every s. b. find a position function r that describes the motion if it occurs with speed .
Answer:
Answer to An object moves clockwise around a circle centered at the origin with radius 6 m beginning at ... 6 M Beginning At The Point (0,6) B. Find A Position Function R That Describes The Motion If It Occurs With Speed E T A. R(t)= S The Motion Of The Object Moves With A Constant Speed, Completing 1 Lap Every 12 S.
Explanation:
one of the lady spartans was falling to the ground after dunking the winning basket. At the end of her fall, she was falling 4 m/s. If she was 60kg, how much potential energy did she have at the top of her jump?
Answer:
15 is the correct answer I.t.
In Case 1, a mass M hangs from a vertical spring having spring constant k and is at rest in its equilibrium position. In Case 2 the mass has been lifted a distance D vertically upward. If we define the potential energy in Case 1 to be zero, what is the potential energy of Case 2
Answer: hello your question is incomplete attached below is the complete question
answer : 1/2 KD^2 ( option A )
Explanation:
P.E ( potential energy ) = mgd
In case 1 P.E = 0 i.e. mgd = 0
Given that in case 2 the Mass M had moved through the Distance D by the compression of the spring
The potential energy of the M in case 2
= P.E of M at rest + P.E of the spring
= 0 + 1/2 KD^2
With explanation pls
Answer:
[tex](x \times 1) = (400 \times 2.5) \\ x = 1000 \: newtons[/tex]
[tex]y = 0[/tex]
If we convert a circuit into a current source with parallel load it is called?
Answer:
If we convert a circuit into a current source with parallel load it is called source transformation
How long would it take a 4,560 watt motor to raise a 166 kg piano to an apartment window
15 meters above the ground?
Answer:
Explanation:
We need the power equation here:
P = W/t where W is work and is defined as
W = F*displacement.
Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:
w = mg so
w = 166(9.8) so
w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:
[tex]4560=\frac{(1600)(15)}{t}[/tex] and isolating the unknown:
[tex]t=\frac{(1600)(15)}{4560}[/tex] so
t = 5.3 seconds
You want to produce a magnetic field of magnitude 5.50 x 10¹ T at a distance of 0.0 6 m from a long, straight wire's center. (a) What current is required to produce this field? (b) With the current found in part (a), how strong is the magnetic field 8.00 cm from the wire's center?
Answer:
(a) I = 1650000 A
(b) 4.125 T
Explanation:
Magnetic field, B = 5.5 T
distance, r = 0.06 m
(a) Let the current is I.
The magnetic field due to a long wire is given by
[tex]B =\frac{\mu o}{4\pi }\frac{2 I}{r}\\5.5= 10^{-7}\times \frac{2\times I}{0.06}\\I =1650000 A[/tex]
(b) Let the magnetic field is B' at distance r = 0.08 m.
[tex]B =\frac{\mu o}{4\pi }\frac{2 I}{r}\\B = 10^{-7}\times \frac{2\times 1650000}{0.08}\\B'= 4.125 T[/tex]
Please help! ❤️
I’ll make you the Brainlyest, I can’t get this one wrong.
Find the period of the leg of a man who is 1.83 m in height with a mass of 67 kg. The moment of inertia of a cylinder rotating about a perpendicular axis at one end is ml2/3. Write your answer with one decimal place.
Answer:
2.2 s
Explanation:
Using the equation for the period of a physical pendulum, T = 2π√(I/mgh) where I = moment of inertia of leg about perpendicular axis at one point = mL²/3 where m = mass of man = 67 kg and L = height of man = 1.83 m, g = acceleration due to gravity = 9.8 m/s² and h = distance of leg from center of gravity of man = L/2 (center of gravity of a cylinder)
So, T = 2π√(I/mgh)
T = 2π√(mL²/3 /mgL/2)
T = 2π√(2L/3g)
substituting the values of the variables into the equation, we have
T = 2π√(2L/3g)
T = 2π√(2 × 1.83 m/(3 × 9.8 m/s² ))
T = 2π√(3.66 m/(29.4 m/s² ))
T = 2π√(0.1245 s² ))
T = 2π(0.353 s)
T = 2.22 s
T ≅ 2.2 s
So, the period of the man's leg is 2.2 s
Give an example of a vertical motion with a positive velocity and a negative acceleration. Give an example of a vertical motion with a negative velocity and a negative acceleration.
Answer:
An example of positive velocity is throwing a ball upwards
An example of downward vertical velocity is when an object is dropped, for example a ball dropped from a height
Explanation:
In a vertical movement the acceleration is always downwards, therefore negative since it is created by the attraction of the Earth on the body.
An example of positive velocity is throwing a ball upwards
An example of downward vertical velocity is when an object is dropped, for example a ball dropped from a height
magnetism/ magnetic field ana magnetic forces
Answer:
Magnetism is a physical phenomenon that manifests itself in a force acting between magnets or other magnetized or magnetisable objects, and a force acting on moving electric charges, such as in current-carrying cables. The force action takes place by means of a magnetic field, which is generated by the objects themselves or otherwise. There are natural and artificial magnets. All magnets have two poles called the north pole and the south pole. The north pole of one magnet repels the north pole of another magnet and attracts the south pole of another magnet; the same with south poles.
what is the magnitude of an electric field (in 106 n/c) that balances the weight of a plastic sphere of mass 2.1 g that has been charged to 3.0 nc
Answer:
[tex]E=6.86\times 10^6\ N/C[/tex]
Explanation:
Given that,
Mass of the sphere, m = 2.1 g = 0.0021 kg
Charge, q = 3 nC
We need to find the magnitude of the electric field that balanced the weight of sphere. Let it is E. So,
qE = mg
[tex]E=\dfrac{mg}{q}[/tex]
Put all the values,
[tex]E=\dfrac{0.0021\times 9.8}{3\times 10^{-9}}\\\\E=6.86\times 10^6\ N/C[/tex]
So, the magnitude of the elecric field is [tex]6.86\times 10^6\ N/C[/tex].
how can you prove that acceleration is a derived unit
a = (dx / dt)²
Explanation: Unit of distance is m (metres) and unit of time is s (seconds) speed v is first derivative of distance x versus time:
v = dx / dt, unit is m/s. Acceleration is second derivative of
speed versus time a = (dx / dt)² = (dv/dt) , unit is m/s²
Answer:
Explanation:
Acceleration is derived unit because it has two fundamental units involved i.e. meter and second square.
What do interplanetary space missions study?
the moon
stars in other galaxies
planets in the solar system
the sun
Answer:
C. Planets in the solar systemExplanation:
The one above is incorrect, and I know this is late. Even if it doesn't help you I hope it helps people in the future! YES I AM TALKING ABOUT YOU FUTURE PEOPLE!! I know this is the answer because I have taken 5.11 Quiz: Uncrewed Spacecraft in K12. There will only be the questions and correct answers below.
1. Which planetary body was Spirit designed to explore?
Mars.
2. What is the name of the most distant manmade object in space? (Credit: shathaadnan64/lak521)
Voyager 1.
3. Which group was designed to study Saturn? (Credit: Brainly User/snowballandtigoya1xa
Voyager 1, Huygens, and Cassini.
4. Why are scientists interested in exploring Mars?
Possible evidence of life.
5. What do interplanetary space missions study?
Planets in the solar system.
Have an amazing day!!
One of the wavelengths of light emitted by hydrogen atoms under normal laboratory conditions is at ?0 = 656.3nm in the red portion of the electromagnetic spectrum. In the light emitted from a distant galaxy this same spectral line is observed to be Doppler-shifted to ? = 953.3nm , in the infrared portion of the spectrum.
How fast are the emitting atoms moving relative to the earth?
Answer:
1.07 × 10⁸ m/s
Explanation:
Using the relativistic Doppler shift formula which can be expressed as:
[tex]\lambda_o = \lambda_s \sqrt{\dfrac{c+v}{c-v}}[/tex]
here;
[tex]\lambda _o[/tex] = wavelength measured in relative motion with regard to the source at velocity v
[tex]\lambda_s =[/tex] observed wavelength from the source's frame.
Given that:
[tex]\lambda _o[/tex] = 656.3 nm
[tex]\lambda_s =[/tex] 953.3 nm
We will realize that [tex]\lambda _o[/tex] > [tex]\lambda_s[/tex]; thus, v < 0 for this to be true.
From the above equation, let's make (v/c) the subject of the formula: we have:
[tex]\dfrac{\lambda_o}{\lambda_s}=\sqrt{\dfrac{c+v}{c-v}}[/tex]
[tex]\Big(\dfrac{\lambda_o}{\lambda_s} \Big)^2=\dfrac{c+v}{c-v}[/tex]
[tex]\dfrac{v}{c} =\dfrac{\Big(\dfrac{\lambda_o}{\lambda_s} \Big)^2-1}{\Big(\dfrac{\lambda_o}{\lambda_s} \Big)^2+1}[/tex]
[tex]\dfrac{v}{c} =\dfrac{\Big(\dfrac{656.3}{953.3} \Big)^2-1}{\Big(\dfrac{656.3}{953.3} \Big)^2+1}[/tex]
[tex]\dfrac{v}{c} =0.357[/tex]
v = 0.357 c
To m/s:
1c = 299792458 m/s
∴
0.357c = (299 792 458 × 0.357) m/s
= 107025907.5 m/s
= 1.07 × 10⁸ m/s
Which statement is true?
a particle of violet light has less energy than a particle of red light
a particle of violet light has more energy than a particle of red light
a particle of violet light has exactly the same energy as a particle of red light
particles of light do not have any energy, regardless of what color the light is
a particle of violet light has exactly the same energy as a particle of red light
compare the time period of two pendulums of length 4m and 9m
area= length × length
area = 4m × 9m
ans 36
You drive past a potential parking space in center city. Your new car is travelling at 85% the speed of light. If your car is 6.0 m long (which you measured the day you bought it) and you observe the space to be 3.0 m, should you try to park? Why is your friend on the sidewalk (who hasn't studied relativity) so sure that you can park? How does the situation appear to him?
Answer:
We should not try to park the car because its rest length is greater than the space available.
The car seems to be approximately equal to the friend (L = 3.16 m). Due to this reason he is sure to park.
Explanation:
We should not try to park the car because its rest length is greater than the space available.
The friend is sure about parking because the car appears short in length to him. For this, we will solve Einstein's length contraction formula from theory of relativity:
[tex]L = L_o\sqrt{1-\frac{v^2}{c^2}}[/tex]
where,
L = Relative length observed by friend = ?
L₀ = rest length = 6 m
v = relative speed = 85% of speed of light = 0.85c
Therefore,
[tex]L = (6\ m)\sqrt{1-\frac{(0.85c)^2}{c^2}}[/tex]
L = 3.16 m
Hence, the car seems to be approximately equal to the friend. Due to this reason he is sure to park.
PLEASE HELPPPPPPPPPP
Answer:
13.09 s
Explanation:
From the question given above, the following data were obtained:
Power (P) = 275 W
Work (W) = 3600 J
Time (t) =?
Power is defined as the rate at which work is done. Mathematically, it can be expressed:
Power (P) = Work (W) / time (t)
P = W/t
With the above formula, we can obtain the time taken for the swimmer to accomplish the work. This can be obtained as follow:
Power (P) = 275 W
Work (W) = 3600 J
Time (t) =?
P = W/t
275 = 3600/t
Cross multiply
275 × t = 3600
Divide both side by 275
t = 3600 / 275
t = 13.09 s
Thus, it will take the swimmer 13.09 s to accomplish the work.
(10) The use of Doppler radar for speed detection and enforcement on the roads is very common and has been in use for a long time. Suppose a 10 GHz radar (also called radar gun or speed gun) measures the speed of a car at 120 km/h moving towards the radar gun. a. What is the change in the frequency of the reflected wave due to the speed of the car b. Calculate the sensitivity of the device in [Hz/km].
Answer:
The sensitivity of the device = 1.234 Hz per km
Explanation:
Given
Frequency (f) = 10 gHz
Speed of the car = 120 Km/h
As per the doppler’s effect
V = (change in frequency /frequency) *(c/2)
Substituting the given values, we get –
Change in frequency = {(2*10^9*120)/(3*10^8)} * (1000/3600)
Change in frequency = 37.03 Hz
b) speed of light = wavelength * frequency
3*10^8 = wavelength * 10*10^9
Wavelength = 0.03 m
Sensitivity = change in frequency /wavelength = 37.03/0.03 = 1234 Hz/m
1.234 Hz per km
If the child has a mass of 13.9 kg, calculate the magnitude of the force in newtons the mother exerts on the child under the following conditions. (b) The elevator accelerates upward at 0.898 m/s2. 148.702 N
The elevator accelerates upward at an acceleration, then the magnitude of the force is 148.84 N.
What is Force?The force is the action of push or pull which makes an object to move or stop.
Given the mass of child m =13.9 kg, acceleration a =0.898 m/s², then the force will be given by
F = m(g-a)
F = 13.9 x (9.81 - (-0.898))
F = 148.84 N
Thus, the magnitude of the force is 148.84 N.
Learn more about force.
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What is the first quantum number of a 252 electron in phosphorus,
1322s22p3s23p3?
A. n=0
B. n= 3
O
C. n = 1
O D. n = 2
Answer:
the correct answer is B
Explanation:
The quantum numbers are the constants obtained when solving the Schrodinger equation, the first quantum number or principal quantum number (n), can take values from zero to infinity.
This quantum number is placed as a coefficient in the quantum distribution.
In this case for phosphorus, the number is n = 3
the correct answer is B
Hey guys....
What is the advantage of a capacitor as it stores charge?
5N
5 N
19 N
19 N
Pls help look at the pic
Answer:
b. is the correct answer ....
How are the Northern Lights are formed.
Answer:
Bottom line: When charged particles from the sun strike atoms in Earth's atmosphere, they cause electrons in the atoms to move to a higher-energy state. When the electrons drop back to a lower energy state, they release a photon: light. This process creates the beautiful aurora, or northern lights.Explanation:
^-^I hope it's help u