1-4 help pls if u know it
Answer:
c,B,a,d i guess i m not sure it is the guessing
what is the diffrence between scalar and vector physical quantites write all examples that you know about each of them
Answer:
Scalar quantity is defined as the physical quantity with magnitude and no direction.
There are plenty of scalar quantity examples, some of the common examples are:
Mass
Speed
Distance
Time
Area
Volume
Density
Temperature
A vector quantity is defined as the physical quantity that has both direction as well as magnitude.
Vector quantity examples are many, some of them are given below:
Linear momentum
Acceleration
Displacement
Momentum
Angular velocity
Force
Electric field
Polarization
In a photoelectric effect experiment, light from a blue LED (wavelength = 405 nm) is directed onto a piece of sodium. It is observed that when V = 0.52 volts, the current measured at the collector drops to zero. What is the work function of the sodium? (a) 0.85 eV (b) 2.5 eV (c) 1.6 eV (d) 3.6 eV (e) 0.088 eV 100% What is the highest velocity of an ejected electron, just above the surface of the sodium? (a) 680000 m/s (b) 300000 m/s (c) 430000 m/s 100% Now we decrease the power of the LED, keeping the wavelength fixed. Which of the following statements is true? (a) The maximum velocity of any ejected electrons will decrease. (b) The minimum possible time to eject an electron (relative to when the LED is turned on) will increase.
Answer:
1. (b) 2.5 eV
2. (c) 430000 m/s
3. (a) The maximum velocity of any ejected electrons will decrease.
Explanation:
1)
From Einstein's Photoelectric Equation:
hc/λ = K.E + ∅
∅ = hc/λ - K.E
∅ = hc/λ - eV
where,
e = charge on electron = 1.6 x 10⁻¹⁹ C
V = Stopping Potential = 0.52 volts
h = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength = 405 nm = 4.05 x 10⁻⁷ m
∅ = Work Function = ?
Therefore,
∅ = (6.625 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(4.05 x 10⁻⁷ m) - (1.6 x 10⁻¹⁹ C)(0.52 volts)
∅ = 4.9 x 10⁻¹⁹ J - 0.832 x 10⁻¹⁹ J
∅ = (4.075 x 10⁻¹⁹ J)(1 eV)/(1.6 x 10⁻¹⁹ J)
∅ = 2.5 eV
therefore, correct answer is"
(b) 2.5 eV
2)
K.E = (1/2)mv² = eV
where,
m = mass of electron = 9.1 x 10⁻³¹ kg
v = speed = ?
therefore,
(1/2)(9.1 x 10⁻³¹ kg)v² = (1.6 x 10⁻¹⁹ C)(0.52 volts)
v = √(0.18 x 10¹² m²/s²)
v = 0.43 x 10⁶ m/s = 430000 m/s
Correct option is:
(c) 430000 m/s
3.
The decrease in power at constant wavelength means decrease in voltage, that results in the decrease of kinetic energy of electrons. So, correct option is:
(a) The maximum velocity of any ejected electrons will decrease.
Assignment 1. Define Couple?
A cloth hat and large rock are dropped at at the same time on the moon
Answer:
What’s the question??
Explanation:
2.27 A gas is compressed from V1= 0.3 m3, p1=1 bar to V2= 0.1 m3, p2 =3 bar. The pressure and
the volume are related linearly during the process. For the gas, find the
work, in kJ.
2.29 A gas expands from an initial state where p1=500kPa and V1=0.1m3 to a state
end where p2= 100 kPa. The relationship between pressure and volume during the process is
pV=constant. Schematize the process in a p-V diagram and determine the work, in
kJ.
Answer:
-40 kJ
80 kJ
Explanation:
Work is equal to the area under the pressure vs volume graph.
W = ∫ᵥ₁ᵛ² P dV
2.27) Pressure and volume are linearly related. When we graph P vs V, the area under the line is a trapezoid. So the work is:
W = ½ (P₁ + P₂) (V₂ − V₁)
W = ½ (100 kPa + 300 kPa) (0.1 m³ − 0.3 m³)
W = -40 kJ
2.29) Pressure and volume are inversely proportional:
pV = k
The initial pressure and volume are 500 kPa and 0.1 m³. So the constant is:
(500) (0.1) = k
k = 50
The final pressure is 100 kPa. So the final volume is:
(100) V = 50
V = 0.5
The work is therefore:
W = ∫ᵥ₁ᵛ² P dV
W = ∫₀₁⁰⁵ (50/V) dV
W = 50 ln(V) |₀₁⁰⁵
W = 50 (ln 0.5 − ln 0.1)
W ≈ 80 kJ
) The square plates of a 5000-pF parallel-plate capacitor measure 50 mm by 50 mm and are separated by a dielectric that is 0.23 mm thickand totally fills the region between the plates. The voltage rating (the maximum safe voltage) of the capacitor is 400 V. What is the maximum energy that can be stored in this capacitor without damaging it
Answer:
4 x 10⁻⁴ J
Explanation:
C = 5000 pF, V = 400 V
Energy = CV²/2 = 5000 x 10⁻¹² x 400²/2 = 4 x 10⁻⁴ J
In your research lab, a very thin, flat piece of glass with refractive index 2.30 and uniform thickness covers the opening of a chamber that holds a gas sample. The refractive indexes of the gases on either side of the glass are very close to unity. To determine the thickness of the glass, you shine coherent light of wavelength λ0 in vacuum at normal incidence onto the surface of the glass. When λ0= 496 nm, constructive interference occurs for light that is reflected at the two surfaces of the glass. You find that the next shorter wavelength in vacuum for which there is constructive interference is 386 nm.
Answer:
λ₀= 495.88 nm
Explanation:
To analyze this constructive interference interference experiment by reflection, let's look at two important aspects:
* when a ray of light passes from a medium with a lower index, they refact to another medium with a higher index, the reflected ray has a phase difference of pyres
* When a beam penetrates a material medium, the wavelength of the radiation changes according to the refractive index of the material.
λₙ = λ₀ / n
when we introduce these aspects in the expression of contributory interference, it remains
2 d sin θ = (m + ½) λ₀ / n
In general, reflection phenomena are measured at an almost normal angle, whereby θ = π/2 and sin θ = 1
2 d = (m +1/2) λ₀/ n
2n d = (m + ½) λ₀
Let's apply this expression to our case
d = (m + ½) λ₀ / 2n
Suppose we measure on the first interference, this is m = 0
d = ½ λ₀ / 2n
let's calculate
d = ½ 496 10⁻⁹ / (2 2.30)
d = 53.9 10-9 m
This is the thickness of the glass, the next wavelength that gives constructive interference is
λ₀ = 2 n d / (m + ½)
let's calculate
λ₀ = 2 2.3 5.39 10-8 / (1 + ½)
λ₀= 4.9588 10-7 m
λ₀= 495.88 nm
A ball is launched directly upward and ultimately reaches a height of 40 ft on a day when the wind is gusting in different directions. From the time the ball is launched until it reaches a height of 20 ft off the ground the wind is blowing at constant 20 mph to the right. From that time to the time the ball has reached the top and traveled back down to a height of 20 ft the wind is blowing at constant 20 mph to the left. As it travels from 20 ft high back to the ground the wind again blows at a constant 20 mph to the right, where will the ball land?
Recall that
v² - u² = 2 a ∆x
where u and v are initial and final velocities, respectively; a is acceleration; and ∆x is the change in position.
We can use this formula to determine the launch speed of the ball. In the vertical direction, the ball has acceleration g in the downward direction, where g = 32.2 ft/s². At its maximum height, the ball has 0 vertical velocity. So we have
0² - u² = 2 (-32.2 ft/s²) (40 ft)
==> u ≈ 50.75 ft/s
Now, the ball's height y at time t is given by
y = u t - 1/2 g t²
Find at which time t the ball covers the first 20 ft of its trajectory:
20 ft = (50.75 ft/s) t - 1/2 g t²
==> t ≈ 0.462 s
(there is a second solution, t ≈ 2.69 s, which corresponds to the time it takes for the ball to return to this height as it's falling back down)
During this first interval, the ball's horizontal position x is
x = (20 mph) t ≈ (29.33 ft/s) t
so that at the moment the ball reaches a height of 20 ft, it will have moved
x = (29.33 ft/s) (0.462 s) ≈ 13.5 ft
to the right. (So we've take the right to be positive and the left to be negative.)
In the upper half of its trajectory, when the wind changes direction, the ball's horizontal position is given by
x = 13.5 ft - (29.33 ft/s) t
Note that t = 0 here means we now take the ball's current position to be the "initial" one. So the time we found earlier for when the ball has a height of 20 ft as it's falling back down is actually t = 2.69 s - 0.462 s ≈ 2.23 s. At this point, the ball's horizontal position is
x = 13.5 ft - (29.33 ft/s) (2.69 s - 0.462 s) ≈ -51.8 ft
or about 51.8 ft to the left of where it started.
The wind changes direction again, so that the ball's position at time t is now
x = -51.8 ft + (29.33 ft/s) t
Solving y = 0 for t gives the time when the ball reaches the ground:
0 = (50.75 ft/s) t - 1/2 g t²
==> t ≈ 3.15 s
Again, this is the time it takes for the ball to reach the ground since it was launched, while the position function takes t = 0 to refer to the moment the ball is 20 ft above the ground. So once it hits the ground, it will be
x = -51.8 ft + (29.33 ft/s) (3.15 s - 2.69 s) ≈ -38.3 ft
which means the ball lands on the ground about 38.3 ft to the left of where it started.
I will give you branilest
Mrs. LaCross leaves school and accidentally leaves her coffee mug on the roof of her car as shown in the picture below.
She was traveling at a constant pace until a student rushes in front of her not using the sidewalks and crosswalks and she had to slam on her brakes. What will happen to her coffee mug?
[ Select ]
a. The mug will move side by side
b. The mug will move backwards
c. The mug will move forward
d. The mug will not move
Answer:
the mug will moveforwards
Question 4
5 pts
What is microscopic and floats in the ocean?
Plankton
Benthos
Nekton
© Fish
Answer:
Plankton is the correct answer I think
Two insulated copper wires of similar overall diameter have very different interiors. One wire possesses a solid core of copper, with a circular cross section of radius 1.53 mm. The other wire is composed of 19 strands of thin copper wire bundled together. Each strand has a circular cross section of radius 0.306 mm. The current density ???? in each wire is the same. ????=1750 A/m2 Two circles. One circle is solid, whereas the other contains 19 tightly packed smaller circles How much current does each wire carry? solid wire current: A stranded wire current: A The resistivity of copper is ????=1.69×10−8 Ω·m. What is the resistance of a 3.25 m length of each wire? solid wire resistance: Ω stranded wire resistance: Ω
Answer:
a
Solid Wire [tex]I = 0.01237 \ A [/tex]
Stranded Wire [tex]I_2 = 0.00978 \ A [/tex]
b
Solid Wire [tex]R = 0.0149 \ \Omega [/tex]
Stranded Wire [tex]R_1 = 0.0189 \ \Omega [/tex]
Explanation:
Considering the first question
From the question we are told that
The radius of the first wire is [tex]r_1 = 1.53 mm = 0.0015 \ m[/tex]
The radius of each strand is [tex]r_0 = 0.306 \ mm = 0.000306 \ m[/tex]
The current density in both wires is [tex]J = 1750 \ A/m^2[/tex]
Considering the first wire
The cross-sectional area of the first wire is
[tex]A = \pi r^2[/tex]
= > [tex]A = 3.142 * (0.0015)^2[/tex]
= > [tex]A = 7.0695 *10^{-6} \ m^2 [/tex]
Generally the current in the first wire is
[tex]I = J*A[/tex]
=> [tex]I = 1750*7.0695 *10^{-6}[/tex]
=> [tex]I = 0.01237 \ A [/tex]
Considering the second wire wire
The cross-sectional area of the second wire is
[tex]A_1 = 19 * \pi r^2[/tex]
=> [tex]A_1 = 19 *3.142 * (0.000306)^2[/tex]
=> [tex]A_1 = 5.5899 *10^{-6} \ m^2[/tex]
Generally the current is
[tex]I_2 = J * A_1[/tex]
=> [tex]I_2 = 1750 * 5.5899 *10^{-6} [/tex]
=> [tex]I_2 = 0.00978 \ A [/tex]
Considering question two
From the question we are told that
Resistivity is [tex]\rho = 1.69* 10^{-8} \Omega \cdot m[/tex]
The length of each wire is [tex]l = 6.25 \ m[/tex]
Generally the resistance of the first wire is mathematically represented as
[tex]R = \frac{\rho * l }{A}[/tex]
=> [tex]R = \frac{ 1.69* 10^{-8} * 6.25 }{ 7.0695 *10^{-6} }[/tex]
=> [tex]R = 0.0149 \ \Omega [/tex]
Generally the resistance of the first wire is mathematically represented as
[tex]R_1 = \frac{\rho * l }{A_1}[/tex]
=> [tex]R_1 = \frac{ 1.69* 10^{-8} * 6.25 }{5.5899 *10^{-6} }[/tex]
=> [tex]R_1 = 0.0189 \ \Omega [/tex]
calculate the monentun pf 75 kg bicycle and boy who has ghe velocitg of 3m/s
Explanation:
n=75 kg
v=3m/s
m=n×v
m=75x3
m= 225n
Which of the following is a description of the Remote Associates Test (RAT)?
Answer:
The description is outlined throughout the clarification section following, and according to the given word.
Explanation:
Throughout the 1960s, Sarnoff Mednick created the RAT as a tool used for testing imaginative convergent thought. Through each RAT test query lists a set of terms, which demands that we have a single additional term that will tie any of the others around. Those other words may also be related in something like a variety of ways, such as through creating a compound word or perhaps a semantic connexon.what are the applications of measurement?
22/22 is an even number greater than 20?
Answer:
yes
Explanation:
becuse it is an even that is 2 number then 20
Answer:
Yes
Explanation:
It is because 22 is greater than 20
a strong inductive argument must have true premises
True
False
5
Find the resultant of the following four forces.
A= 25 N due north
B = 50 N due east
C= 30 N due west
D=40 N due south
25+50-30-40 = 0
north and east are positive directions, south and west are negative
hope this helps
also hope u enjoy a pic of my crush lol
If a car with a mass of 4000 kg is accelerating at a rate of 2 ms and hits a tree what force does it have
That depends on the car's speed at the moment of impact, and how long it takes to stop after the impact.
It is NOT 8,000N. That answer would come from a totally incorrect application of " F = m a " . 8,000 Newtons is what it takes to accelerate that car in the first place, long before it hits the tree.
Force can be described as either a pull or a push
Now when a body with mass and acceleration hits an object, we say a collision has taken place, hence there will be transfer of energy within the system
Give data
mass = 4000kg
acceleration = 2m/s^2
We know that force is given as
Force = mass x acceleration
Substitute our given data into the expression for force
Force = 4000 x 2Force = 8000N
For more information on force kindly visit
brainly.com/question/18038995
Four students give their teacher identical apples. Each student sets his or her apple on a different stack of books. Which
apple has the most potential energy?
Answer:
Diagram B.
Explanation:
We'll begin by defining potential energy.
This is given below:
Potential energy is the energy stored in an object due to its position. Mathematically, it is expressed as:
P.E = m × g × h
Where:
P.E is the potential energy.
m is the mass of the object.
g is the acceleration due to gravity.
h is the height to which the object is located.
From:
P.E = m × g × h
We can say that the potential energy (P.E) is directly proportional to the height (h) to which the object is located. This implies that as the height increase, the potential energy of the object will also increase and as the height decrease, the potential energy of the object will also decrease.
Now, considering the question given above, we can see that the height of the object is greater in diagram B. Therefore, The potential energy of the object is greater in diagram B.
Answer:
The answer s B
Explanation:
If electrons are added to an object the object becomes
charge.
negative
positive
neutral
nothing happens
Answer:
It can be either, depending on how much and how you add the electrons
Think about the way your body works when you eat an ice cream cone. Provide an explanation of how organs are working together as a system to help you eat the cone. Describe one organ system and how its parts combine to get your body nutrition from the food.
PLZ HELP
Answer:
Explanation:
BAHAHAHAH karely omg HAHAHA un idke
Lana's class is studying the various kinds of energy found on a playground
Which of the following would be the BEST way to test for an equal transformation of energy on a playground?
СА
Using the slide, Lana could measure her kinetic energy when she was climbing up the ladder, measure her potential energy before she slid down, and her total energy used at the bottom of the slide. If the amount of potential
energy and kinetic energy added up to equal the total amount of energy used, it would show an equal transformation of energy
OB
Using the slido, Lana could measure her potential and kinetic energy sitting at the top of the slide, and then she could measure her kinetic and potential energy at various points while sliding to the bottom of the total value of
her potential energy and her kinetic energy were equal at every measuremont, it would show that there had been an equal transformation
C
Using the swing, Lana could measure her potential energy when she was sitting still on the swing, and she could measure her kinetic energy when the swing was in motion. If the kinetic energy was twice the amount of her
potential energy, it would show there had boon an equal transformation of potential energy to kinetic energy
D
Using the soesaw, Lana could measure her potential energy when she was in motion, and she could measure her kinetic energy when she was resting. If her kinetic and potential energy were equal, it would show that there
had been an equal transformation
If the amount of potential energy and kinetic energy added up to equal the total amount of energy used, it would show an equal transformation of energy.
What is Energy?This can be defined as the ability or capacity to do work. The potential and kinetic energy equals the total amount of energy involved when Lana was on the playground.
This depicts an equal transformation of energy which is why the most appropriate choice in this scenario is option A.
Read more about Energy here https://brainly.com/question/582060
how does energy transfer between objects
Answer:
Object A runs into Object B. The force that object A has will transfer from Object A to Object B. But during this transfer you will loose some energy, therefore object B will not travel as fast.
Explanation:
PLEASE PROVIDE EXPLANATION.
THANK YOU!!
Answer:
11,000 kg
(a) 11.2 m/s
(b) 1.6 m/s
Explanation:
Momentum is conserved.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(2200 kg) (60.0 km/h) + m (0 km/h) = (2200 kg) (10 km/h) + m (10 km/h)
132,000 kg km/h = 22,000 kg km/h + m (10 km/h)
110,000 kg km/h = m (10 km/h)
m = 11,000 kg
Momentum is conserved.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(m) (-v) + (2m) (5v) = (m) (v₁) + (2m) (v₂)
-mv + 10mv = m v₁ + 2m v₂
9mv = m (v₁ + 2 v₂)
9v = v₁ + 2 v₂
Since the collision is elastic, kinetic energy is also conserved.
½ m₁u₁² + ½ m₂u₂² = ½ m₁v₁² + ½ m₂v₂²
m₁u₁² + m₂u₂² = m₁v₁² + m₂v₂²
(m) (-v)² + (2m) (5v)² = m v₁² + (2m) v₂²
mv² + 50mv² = m v₁² + 2m v₂²
51mv² = m (v₁² + 2 v₂²)
51v² = v₁² + 2 v₂²
We know v = 1.60 m/s. So the two equations are:
14.4 = v₁ + 2 v₂
130.56 = v₁² + 2 v₂²
Solve the system of equations using substitution.
130.56 = (14.4 − 2 v₂)² + 2 v₂²
130.56 = 207.36 − 57.6 v₂ + 4 v₂² + 2 v₂²
0 = 6 v₂² − 57.6 v₂ + 76.8
0 = v₂² − 9.6 v₂ + 12.8
v₂ = [ 9.6 ± √(9.6² − 4(1)(12.8)) ] / 2(1)
v₂ = 1.6 or 8
If v₂ = 1.6 m/s, then v₁ = 14.4 − 2 v₂ = 11.2 m/s.
If v₂ = 8 m/s, then v₁ = 14.4 − 2 v₂ = -1.6 m/s.
We know v₁ can't be -1.6 m/s, since that would mean puck A didn't change speeds after the collision. Therefore, v₁ = 11.2 m/s and v₂ = 1.6 m/s.
what is E=mc^2?
please explain..
Answer:
In physics, mass–energy equivalence is the principle that anything having mass has an equivalent amount of energy and vice ve
A cube with sides 12 cm is submerged in water to a depth of 30 cm. Given density of water is 1000 kg/m3. Calculate the pressure at the bottom surface of the cube due to water.
Answer:
P=2940 Pa
Explanation:
Given that,
Side of a cube, a = 12 cm
It is submerged to depth of 30 cm
The density of water, d = 1000 kg/m^3
We need to find the pressure at the bottom surface of the cube. We know that the pressure exerted is given by :
[tex]P=d gh\\\\P=1000\ kg/m^3\times 9.8\ m/s^2\times 0.3\ m\\\\P=2940\ Pa[/tex]
So, 2940 Pa of pressure is exerted at the bottom surface of the cube due to water.
1. Wind
A. Definition
B. What Heat Transfer Causes
c. Types
Answer:
B . a heat transfer caused
The statement "All Romans are Italians" means the same as "If you are Roman, then you are Italian"
True
False
A large research balloon containing 2.00 × 10^3 m^3 of helium gas at 1.00 atm and a temperature of 15.0°C rises rapidly from ground level to an altitude at which the atmospheric pressure is only 0.900 atm. Assume the helium behaves like an ideal gas and the balloon’s ascent is too rapid to permit much heat exchange with the surrounding air.
Required:
a. Calculate the volume of the gas at the higher altitude.
b. Calculate the temperature of the gas at the higher altitude.
c. What is the change in internal energy of the helium as the balloon rises to the higher altitude?
Answer:
a
[tex]T_2 = 276.1 \ K[/tex]
b
[tex]V_2 = 2.13 *10^{3} \ m^3 [/tex]
c
[tex]\Delta U = -1.25 *10^{7} \ J [/tex]
Explanation:
From the question we are told that
The volume of the balloon is [tex]V = 2.00 * 10^3 \ m^3[/tex]
The pressure of helium is [tex]P_1 = 1.00 \ atm= 1.0 *10^{5} \ Pa [/tex]
The initial temperature is [tex]T_1 = 15.0^oC = 288 \ K [/tex]
The pressure of atmosphere is [tex]P_a = 0.900 \ atm[/tex]
Generally the equation representing the adiabatic process is mathematically represented as
[tex]P_1 V_1 ^{\gamma }= P_2 V_2 ^{\gamma }[/tex]
=> [tex]V_2 ^ {\gamma } = \frac{ V_1 ^{\gamma } * P_1 }{P_2}[/tex]
Generally [tex]\gamma[/tex] is a constant with value [tex]\gamma =\frac{5}{3}[/tex] for an ideal gas
So
[tex]V_2 ^ {\frac{5}{3} } = \frac{ ( 2.0 *10^{3}) ^{ \frac{5}{3} } * 1.00 }{0.900}[/tex]
[tex]V_2 = (\sqrt[5]{103.14641852} )^3[/tex]
=> [tex]V_2 = 2.13 *10^{3} \ m^3 [/tex]
Generally the adiabatic process can also be mathematically represented as
[tex]T_1 V_1 ^{\gamma -1 } = T_2 V_2^{\gamma -1 }[/tex]
=> [tex]T_2 = 288 * [\frac{2 * 10^{3}}{ 2.13 *10^{3}} ]^{ \frac{5}{3} -1 }[/tex]
=> [tex]T_2 = 276.1 \ K[/tex]
Generally the ideal gas equation is mathematically represented as
[tex]P_1 V_1 = nRT_1[/tex]
Here R is the gas constant with value [tex]R = 8.314\ J /mol \cdot K[/tex]
[tex]n = \frac{P_1 V_1 }{RT _1}[/tex]
=> [tex]n = \frac{1.0 *10^{5} * 2.0 *10^{3}}{8.314 * 288[/tex]
=> [tex]n = 84362 \ mol[/tex]
Generally change in internal energy i mathematically represented
[tex]\Delta U = n C_v \Delta T[/tex]
Here [tex]C_v[/tex] is the specific heats of gas at constant volume and the value is [tex]C_v = 12.47 J/mol \cdot K[/tex]
[tex]\Delta U = 84362 * 12.47 * [T_2 - T_1 ] [/tex]
[tex]\Delta U = 84362 * 12.47 * [276.1 - 288 ] [/tex]
[tex]\Delta U = -1.25 *10^{7} \ J [/tex]