Answer:
(a)
67.1 s
(b) 2.5 m
(c) 2.5 m
Explanation:
initial speed, u = 0 m/s
final speed, v = 70 m/s
acceleration, a = 5 m/s2
distance, s = 1800 m
(a) Use third equation of motion
[tex]v^2= u^2 + 2 a s \\\\v^2 = 0 + 2 \times 5\times 1800\\\\v =134.2 m/s[/tex]
Let the time is t.
Use first equation of motion
v = u + at
134.2 = 0 + 5 t
t = 67.1 s
(b) Use second equation of motion
[tex]s = u t +0.5 at^2\\\\s = 0 +0.5\times 5\times 1 \\\\s = 2.5 m[/tex]
(c) Use second equation of motion
[tex]s = u t +0.5 at^2\\\\s = 0 +0.5\times 5\times 1 \\\\s = 2.5 m[/tex]
The volume electric charge density of a solid sphere is given by the following equation: The variable r denotes the distance from the center of the sphere, in spherical coordinates. What is the net electric charge (in μC) of the sphere if the radius of the sphere is 0.5 m?
Answer:
62.8 μC
Explanation:
Here is the complete question
The volume electric charge density of a solid sphere is given by the following equation: ρ = (0.2 mC/m⁵)r²The variable r denotes the distance from the center of the sphere, in spherical coordinates. What is the net electric charge (in μC) of the sphere if the radius of the sphere is 0.5 m?
Solution
The total charge on the sphere Q = ∫∫∫ρdV where ρ = volume charge density = 0.2r² and dV = volume element in spherical coordinates = r²sinθdθdrdΦ
So, Q = ∫∫∫ρdV
Q = ∫∫∫ρr²sinθdθdrdΦ
Q = ∫∫∫(0.2r²)r²sinθdθdrdΦ
Q = ∫∫∫0.2r⁴sinθdθdrdΦ
We integrate from r = 0 to r = 0.5 m, θ = 0 to π and Φ = 0 to 2π
So, Q = ∫∫∫0.2r⁴sinθdθdrdΦ
Q = ∫∫∫0.2r⁴[∫sinθdθ]drdΦ
Q = ∫∫0.2r⁴[-cosθ]drdΦ
Q = ∫∫0.2r⁴-[cosπ - cos0]drdΦ
Q = ∫∫∫0.2r⁴-[-1 - 1]drdΦ
Q = ∫∫0.2r⁴-[- 2]drdΦ
Q = ∫∫0.2r⁴(2)drdΦ
Q = ∫∫0.4r⁴drdΦ
Q = ∫0.4r⁴dr∫dΦ
Q = ∫0.4r⁴dr[Φ]
Q = ∫0.4r⁴dr[2π - 0]
Q = ∫0.4r⁴dr[2π]
Q = ∫0.8πr⁴dr
Q = 0.8π∫r⁴dr
Q = 0.8π[r⁵/5]
Q = 0.8π[(0.5 m)⁵/5 - (0 m)⁵/5]
Q = 0.8π[0.125 m⁵/5 - 0 m⁵/5]
Q = 0.8π[0.025 m⁵ - 0 m⁵]
Q = 0.8π[0.025 m⁵]
Q = (0.02π mC/m⁵) m⁵
Q = 0.0628 mC
Q = 0.0628 × 10⁻³ C
Q = 62.8 × 10⁻³ × 10⁻³ C
Q = 62.8 × 10⁻⁶ C
Q = 62.8 μC
1. Why does the shape of the lens in your eye change?
To alter the amount of light that enters the eye
to focus the light
to alter the image sent to the brain
Answer:
to focus the link light
Explanation:
Because the lens is flexible and elastic, it can change its curved shape to focus on objects and people that are either nearby or at a distance. ... The ciliary muscles, which are part of the ciliary body, are attached to the lens and contract or release to change the lens shape and curvature.
Answer:
to focus the link light
Explanation:
vote brainliest I never got voted brainliest plssss
Two objects (48.0 and 25.0 kg) are connected by a massless string that passes over a massless, frictionless pulley. The pulley hangs from the ceiling. Find (a) the acceleration of the objects and (b) the tension in the string.
Answer:
a. 3.09 m/s^2
b. 322.52 N
Explanation:
The computation of the acceleration of the object and the tension of the string is as follows:
The acceleration of the system is a
= (m1 - m2) × g ÷ (m1 + m2)
= (48 - 25) × 9.81 ÷ (48 + 25)
= 3.09 m/s^2
b. The tension in the string is T
= 2 × m1 × m2 × g÷ (m1+m2)
= (2 × 48 × 25 × 9.81) ÷ (48 + 25)
= 322.52 N
LC-circuit of the radio receiver consists of variable capacitor (Cmin= 1 pF, Cmax=10 pF) and inductor
with inductance 1 µH. Determine the wavelength range of this radio receiver.
Answer:
the radio can tune wavelengths between 1.88 and 5.97 m
Explanation:
The signal that can be received is the one that is in resonance as the impedance of the LC circuit.
X = X_c - X_L
X = 1 / wC - w L
at the point of resonance the two impedance are equal so their sum is zero
X_c = X_L
1 / wC = w L
w² = 1 / CL
w = [tex]\sqrt{\frac{1}{CL} }[/tex]
let's look for the extreme values
C = 1 10⁻¹² F
w = [tex]\sqrt{\frac{1}{ 1 \ 10^{-12} \ 1 \ 10^{-6}} }[/tex]
w = [tex]\sqrt{1 \ 10^{18}}[/tex]
w = 10⁹ rad / s
C = 10 10⁻¹² F
w = [tex]\sqrt{\frac{1}{10 \ 10^{-12} \ 1 \ 10^{-6}} }[/tex]Ra 1/10 10-12 1 10-6
w = [tex]\sqrt{0.1 \ 10^{18}}[/tex]Ra 0.1 1018
w = 0.316 10⁹ rad / s
Now the angular velocity and the frequency are related
w = 2π f
f = w / 2π
the light velocity is
c = λ f
λ = c / f
we substitute
λ = c 2π/w
we calculate the two values
C = 1 pF
λ₁ = 3 10⁸ 2π / 10⁹
λ₁= 18.849 10⁻¹ m
λ₁ = 1.88 m
C = 10 pF
λ₂ = 3 10⁸ 2π / 0.316 10⁹
λ₂ = 59.65 10⁻¹ m
λ₂ = 5.97 m
so the radio can tune wavelengths between 1.88 and 5.97 m
which of the following is a correct statement. a. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are constant. b. In dc steady state conditions, the voltages across the capacitors are zero and the currents through the capacitance are constant. The current through the inductors are constant and the voltage across the inductances are zero. c. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are zero and the voltage across the inductances are constant. d. WIn dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
Answer:
d. In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
Explanation:
The current through a capacitor is given by i = CdV/dt where C = capacitance of capacitor and V = voltage across capacitor. At steady state dV/dt = 0 and V = constant. So, i = CdV/dt = C × 0 = 0.
So, in dc steady state, the voltage across a capacitor is constant and the current zero.
The voltage across an inductor is given by V = Ldi/dt where L = inductance of inductor and i = current through inductor. At steady state di/dt = 0 and V = constant. So, V = Ldi/dt = L × 0 = 0.
So, in dc steady state, the voltage across an inductor is zero and the current constant.
So, In dc steady state conditions, the voltages across the capacitors are constant and the currents through the capacitance are zero. The current through the inductors are constant and the voltage across the inductances are zero.
The answer is d.
A wave has angular velocity 12 rad/sec and maximum displacement X cm (X= last two digit [1] of your student’s ID). Calculate the maximum acceleration of the wave.
Answer:
[tex]a=1440\ m/s^2[/tex]
Explanation:
Given that,
The angular velocity of a wave, [tex]\omega=12\ rad/s[/tex]
The maximum displacement of the wave, A = 10 cm (let)
The maximum acceleration of the wave is given by :
[tex]a=-A\omega^2[/tex]
Put all the values,
[tex]a=10\times 12^2\\\\a=1440\ m/s^2[/tex]
So, the maximum acceleration of the wave is equal to [tex]1440\ m/s^2[/tex].
13. How many electrons does a complete third electron shell hold?
Answer:
A) 8A complete third electron shell holds 8 electrons
---------------------------
hope it helps...
have a great day!!
Answer:
8
Explanation:
ou charge a piece of aluminum foil (mass = 4.99 g) by touching it to a charged rod. The charged rod gives the aluminum foil a charge of 13 µC. Your professor brings a charged plate over and tells you to put the aluminum foil on top of the plate. To your surprise the aluminum foil hovers motionless in the air above it! Calculate the value of the electric field from the charged plate (assume it is a uniform field and the aluminum foil is a point charge).
Answer:
The appropriate answer is "3761.69 N/C".
Explanation:
Given that:
Mass,
m = 4.99 g
or,
= [tex]4.99\times 10^{-3} \ kg[/tex]
Charge,
q = 13 µC
or,
= [tex]13\times 10^{-6} \ C[/tex]
As we know,
⇒ [tex]F=mg=Eq[/tex]
then,
⇒ [tex]E=\frac{mg}{q}[/tex]
By putting the values, we get
[tex]=\frac{4.99\times 10^{-3}\times 9.8}{13\times 10^{-6}}[/tex]
[tex]=3761.69 \ N/C[/tex]
voltage needed to raise current to 3.75a using 20,20,200 resistor set
Answer: The voltage needed is 35.7 V
Explanation:
Assuming that the resistors are arranged in parallel combination.
For the resistors arranged in parallel combination:
[tex]\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}[/tex]
We are given:
[tex]R_1=20\Omega\\R_2=20\Omega\\R_3=200\Omega[/tex]
Using above equation, we get:
[tex]\frac{1}{R}=\frac{1}{20}+\frac{1}{20}+\frac{1}{200}\\\\\frac{1}{R}=\frac{10+10+1}{200}\\\\R=\frac{200}{21}=9.52\Omega[/tex]
Calculating the voltage by using Ohm's law:
[tex]V=IR[/tex] .....(1)
where,
V = voltage applied
I = Current = 3.75 A
R = Resistance = [tex]9.52\Omega[/tex]
Putting values in equation 1, we get:
[tex]V=3.75\times 9.52\\\\V=35.7V[/tex]
Hence, the voltage needed is 35.7 V
There are six different ways to arrange those resistors.
Each way leads to a different answer.
You didn't tell us how you want them connected.
The attached drawing shows them all.
turn this scentence to repirted speach.
i ate icecream
She said that..........
Answer:
dhfhffuththt9tr8tujtngigjtjrjrjrurur
can anyone answer this fast pls
A parallel-plate capacitor is connected to a battery of electric potential difference V. If the plate separation is decreased, do the following quantities increase, decrease, or remain the same: (a) the capacitor’s capacitance, (b) the potential difference across the capacitor, (c) the charge on the capacitor, (d) the energy stored by the capacitor, (e) the magnitude of the electric field between the plates, and (f ) the energy density of that electric field?
Answer:
a) increases.
b) remains the same.
c) increases.
d) increases.
e) increases.
f) increases.
Explanation:
a)
Since the capacitance of a parallel-plate depends only on geometric constants and the dielectric between the plates, we can use the following expression to asess the value of the capacitance:[tex]C = \epsilon_{0}*\frac{A}{d} (1)[/tex]
where ε₀ = permitivitty of free space
A = area of one of the plates
d= plate separation
As we can see, if the plate separation is decreased, the value of the capacitance must increase.b)
Per definition the capacitance explains the relationship between the charge on one of the conductors, and the potential difference between them, as follows:[tex]C = \frac{Q}{V} (2)[/tex]
Assuming that the capacitor remains connected to the battery when the plate separation is decreased, since the voltage can't change (as it must hold the same voltage than previously since it's directly connected to the battery) the potential difference between plates must remain the same.c)
From B, we know that V in (2) must remain constant. Since we know from (1) that C must increase, this means from (2) that Q must increase too.d)
The energy stored in the electric field between the plates can be expressed as follows in terms of the capacitance C and the potential difference V:[tex]U = \frac{1}{2}* C*V^{2} (3)[/tex]
From (1) in a) and from b) we know that the capacitance C must increase whilst V must remain the same, so U in (3) must increase also.e)
In the capacitor the magnitude of the Electric field between the plates is constant, and is related to the potential difference between them by the following linear relationship:[tex]V = E*d (4)[/tex]
Since we know that V must remain the same, if the distance d decreases, the electris field E must increase in the same ratio in order to keep the equation balanced.f)
The energy density of the electric field is defined as the energy stored between plates by unit volume, as follows:[tex]u = \frac{U}{v} = \frac{\frac{1}{2}* C*V^{2}}{A*d} =\frac{1}{2}* \epsilon_{0}*\frac{A*V^{2} }{A*d*d} = \frac{1}{2} *\epsilon_{0}*E^{2} (5)[/tex]
Since it's proportional to the square of the electric field, and we know from e) that the magnitude of the electric field must increase, u must increase too.after landing aeroplane moment become zero how's?
Answer:
So logically speaking the question you have asked makes no sense
Explanation:
Zero what? After landing where? How what? before asking a question think about how other people will read it.
A stone was dropped off a cliff and hit the ground with a speed of 136 ft/s. What is the height of the cliff
Answer:
Explanation:
Use the equation
[tex]v^2=v_0^2+2a[/tex]Δx
In this dimension (the y dimension...the only one we have to care about for this problem), here's what we know:
a = -32 ft/s/s
v₀ = 0 m/s (since someone was holding the stone still before it was dropped)
v = 136 ft/s
Δx = ??
Filling in:
[tex]136^2=0^2+2(-32)[/tex]Δx so
Δx = [tex]\frac{136^2}{2(-32)}[/tex] so
Δx = -289 feet (negative because the stone dropped that many feet below the point from which it was dropped, but you would answer a height question with the positive of this number. If you were asked how far the stone dropped, it would be negative; if you're asked how tall the cliff is, that would be positive)
20. Using the picture, how many neutrons does lithium have?
Answer:
No. of Neutrons = 3
Explanation:
The atomic number of Lithium is given as 3 in the symbol while the mass number is given as 5.941 which is approximately equal to 6.
Mass Number = No. of Protons + No. of Neutrons = 6
Atomic Number = Number of Electrons = No. of Protons = 3
Therefore,
Mass Number - Atomic Number = (No. of Protons + No. of Neutrons) - No. of Protons
Mass Number - Atomic Number = No. of Neutrons
No. of Neutrons = 6 - 3
No. of Neutrons = 3
Answer:
3
Explanation:
Honestly, it is the only one in the picture and as an answer.
If the temperature of the conductor is increased, the electrons’ speeds decrease
Answer:
HOPE IT HELPS YOU!!!
Explanation:
Mark FadedGirl25 as brainliest
(a) Suppose that a NASCAR race car is moving to the right with a constant velocity of +96 m/s. What is the average acceleration of the car? (b) Twelve seconds later, the car is halfway around the track and traveling in the opposite direction with the same speed. What is the average acceleration of the car?
what change occurs to the mass of an object when a unbalanced
Answer:
The mass decreases
Explanation:
Just smart
A 0.0780 kg lemming runs off a
5.36 m high cliff at 4.84 m/s. What
is its kinetic energy (KE) when it
is 2.00 m above the ground?
Answer:
0.913
Explanation:
k.e=1/2mv square
k.e=1/2×0.078g×23.4256m/s square
k.e=0.913J
The kinetic energy when the lemming is 2.00 m above the ground is approximately 2.56 J (Joules).
To calculate the kinetic energy (KE) of the lemming when it is 2.00 m above the ground, we need to consider the change in its potential energy (PE) as it falls.
The potential energy at a height h is given by:
PE = m g h
Where:
m is the mass of the lemming (0.0780 kg)
g is the acceleration due to gravity (9.8 m/s²)
h is the height above the ground
Given:
Height of the cliff (h) = 5.36 m
Velocity of the lemming (v) = 4.84 m/s
Height above the ground (h') = 2.00 m
The lemming will lose potential energy as it falls from the cliff, which is converted into kinetic energy. Therefore, the kinetic energy when it is 2.00 m above the ground is equal to the difference between its total initial kinetic energy and the potential energy at that height.
Initial potential energy at the top of the cliff:
PE_initial = m g h
Potential energy when it is 2.00 m above the ground:
PE_final = m * g * h'
The change in potential energy is given by:
ΔPE = PE_final - PE_initial
The kinetic energy (KE) when it is 2.00 m above the ground:
KE = ΔPE = -ΔPE (due to energy conservation)
Let's calculate the potential energy at the top of the cliff and when it is 2.00 m above the ground:
PE_initial = m ×g × h
= 0.0780 kg × 9.8 m/s² × 5.36 m
PE_initial ≈ 4.09 J
PE_final = m ×g × h'
= 0.0780 kg ×9.8 m/s² ×2.00 m
PE_final ≈ 1.53 J
The change in potential energy (ΔPE) is:
ΔPE = PE_final - PE_initial = 1.53 J - 4.09 J
ΔPE ≈ -2.56 J
Since the change in potential energy is equal to the kinetic energy, the kinetic energy when the lemming is 2.00 m above the ground is approximately 2.56 J (Joules).
To know more about kinetic energy
https://brainly.com/question/999862
#SPJ2
Wind is caused by ___. the earth's tilt the Coriolis effect temperature differences humidity
I am guessing wind is caused by climate change in the atmosphere
Explanation:
wind is cause by climate change in the atmosphere that depends weather is is breezy really cold or rain and cold
Answer:
caused by the uneven heating of the Earth by the sun and the own rotation.
1000 grams of water is heated from 0 degree to 200 degree . The specific heat of water is 4186 j/kg.°C. Estimate the change in entropy of the water.
Answer:2
Explanation:
If you borrow $12250 and pay $147 in annual interest, the APR on your loan is 1.2% 14.7% 1.23% 7.35%
Answer: 1.2%
Explanation:
Given
If one borrows $12,250
and give $147 interest on it
Then the interest is given from the formula
[tex]\Rightarrow S.I=\dfrac{P\times R\times T}{100}\\\\\Rightarrow 147=\dfrac{12,250\times R\times 1}{100}\\\\\Rightarrow R=\dfrac{147}{122.50}\\\\\Rightarrow R=1.2\%[/tex]
Thus, the annual rate of interest is 1.2%
A helicopter is ascending vertically witha speed of 5.40 m/s. At a height of 105 m above the earth a package is dropped from the helicopter. How much time does is take for the package to reach the ground
Answer: 5.21 s
Explanation:
Given
Helicopter ascends vertically with [tex]u=5.4\ m/s[/tex]
Height of helicopter [tex]h=105\ m[/tex]
When the package leaves the helicopter, it will have the same vertical velocity
Using equation of motion
[tex]\Rightarrow h=ut+\dfrac{1}{2}at^2\\\\\Rightarrow 105=-5.4t+0.5\times 9.8t^2\\\Rightarrow 4.9t^2-5.4t-105=0\\\\\Rightarrow t=\dfrac{5.4\pm \sqrt{5.4^2+4\times 4.9\times 105}}{2\times 4.9}\\\\\Rightarrow t=\dfrac{5.4\pm 45.68}{9.8}\\\\\Rightarrow t=5.21\ s\quad \text{Neglect negative value}[/tex]
So, package will take 5.21 s to reach the ground
Por que nos dias de hoje o futebol é mais técnico, com mas estratégias e mais disputado?
Explanation:
[tex]which \: language \: is \: this[/tex]
[tex]pls \: write \: in \: english[/tex]
[tex]then \: only \: i \: can \: answer \: u[/tex]
[tex]otherwise \: sry[/tex]
The wheels on a skateboard have a diameter of 2.93 inches. If a skateboarder is traveling downhill at 23 miles per hour, determine the angular velocity of the wheels in radians per second.
Answer:
The angular velocity of the wheels is 276.314 radians per second.
Explanation:
The wheels are rolling, which is a combination of rotation and translation, whose center of rotation is the point of contact between the wheel and the ground and the geometrical center of the skateboard experiments pure translation. Then, the angular velocity can be found by using the following kinematic expression:
[tex]\omega = \frac{v}{R}[/tex] (1)
Where:
[tex]\omega[/tex] - Angular velocity, in radians per second.
[tex]v[/tex] - Velocity of the wheel at its center, in inches per second.
[tex]R[/tex] - Radius of the wheel, in inches.
If we know that [tex]v = 404.8\,\frac{in}{s}[/tex] and [tex]R = 1.465\,in[/tex], then the angular velocity of the wheels are:
[tex]\omega = \frac{404.8\,\frac{in}{s} }{1.465\,in}[/tex]
[tex]\omega = 276.314\,\frac{rad}{s}[/tex]
The angular velocity of the wheels is 276.314 radians per second.
The position of a particle changes linearly with time, i.e. as one power of t, as given by the following: h(t) = ( 4.1 t + 5.5 ) meters. Find the speed of the particle, in meters per second.
Answer:
v = 4.1 m / s
Explanation:
Velocity is defined by the relation
v =[tex]\frac{dx}{dt}[/tex]
we perform the derivative
v = 4.1 m / s
Another way to find this magnitude is to see that the velocity on the slope of a graph of h vs t
v = [tex]\frac{\Delta x}{\Delta t}[/tex]
Δx = v Δdt + x₀
h= 4.1 t + 5.5
v = 4.1 m / s
x₀ = 5.5 m
Human vision cuts off on the red side of the spectrum at about 675 nm. What is the energy of a photon (in J) of this wavelength?
Answer:
The energy of a photon is 2.94x10⁻¹⁹ J.
Explanation:
The energy of the photon is given by:
[tex] E = \frac{hc}{\lambda} [/tex]
Where:
h: is Planck's constant = 6.62x10⁻³⁴ J.s
c: is the speed of light = 3.00x10⁸ m/s
λ: is the wavelength = 675 nm
Hence, the energy is:
[tex] E = \frac{hc}{\lambda} = \frac{6.62 \ccdot 10^{-34} J.s*3.00 \cdot 10^{8} m/s}{675 \cdot 10^{-9} m} = 2.94 \cdot 10^{-19} J [/tex]
Therefore, the energy of a photon is 2.94x10⁻¹⁹ J.
I hope it helps you!
9. What part of the eye contains muscles that regulate the amount of light that is allowed to enter the eye?
Answer: the iris
Explanation: I looked it up
Answer:
Iris
Explanation:
Because (iris) has muscles that can expand/contract depends to the amount of light that pupil needs to process/figure out images.
Which of these is a chemical control used to help control invasive species?
using fences
using other species
using herbicides
using barriers
Answer:
a
Explanation:
Using fences.................................
can some one tell the answers
