Answer:
the work function of the metal is 4.167 x 10⁻¹⁹ J .
Explanation:
Given;
wavelength of the incident light, λ = 450 nm = 450 x 10⁻⁹ m
kinetic energy, K.E = 2.5 x 10⁻²⁰ J
The energy of the incident light is calculated as;
[tex]E = hf = \frac{h c}{\lambda} \\\\where;\\\\c \ is \ speed \ of \ light = 3 \times 10^8 \ m/s\\\\ h \ is \ Planck's constant = 6.626 \times 10^{-34} Js \\\\E = \frac{(6.626 \times 10^{-34})(3\times 10^8)}{450 \times 10^{-9}} \\\\E = 4.417 \times 10^{-19} \ J[/tex]
Apply Einstein photoelectric equation to determine the work function of the metal;
E = W + K.E
where;
W is the work function of the metal
W = E - K.E
W = 4.417 x 10⁻¹⁹ J - 2.5 x 10⁻²⁰ J
W = 44.17 x 10⁻²⁰ J - 2.5 x 10⁻²⁰ J
W = 41.67 x 10⁻²⁰ J
W = 4.167 x 10⁻¹⁹ J
Therefore, the work function of the metal is 4.167 x 10⁻¹⁹ J .
The work function of the photon is 4.167*10^19J
The energy of this photon can be calculated as
E = hc/λ
Data given;
λ = 450nm = 450*10^-9mh = 6.626*10^-34JSK.E = 2.5*10^-20Jc = 3.0*10^8m/sEnergy of the Photonsubstituting the values into the equation;
[tex]E = hc / y\\E = \frac{6.626*10^-^3^4*3.0*10^8}{450*10^-^9} \\E = 4.42*10^-^1^9J[/tex]
Work FunctionThe work function of the photon can be calculated as;
E = K.E + Ф
4.42*10^-19 = 2.5*10^-20 + Ф
Ф = [tex]4.42*10^-^1^9 - 2.5*10^-^2^0=4.167*10^-^1^9J[/tex]
The work function of the photon is 4.167*10^-19 J
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A wheel of mass 50 kg has a radius of 0.4 m. It is making 480 rpm. What is the
torque necessary to bring it to rest in 40 seconds?
Solution:
Answer:
The torque necessary to bring the wheel to rest in 40 seconds is 10.4 N·m
Explanation:
The question is with regards to rotational motion
The rotary motion parameters are;
The mass of the wheel = 50 kg
The radius of the wheel = 0.4 m
The rate of rotation of the wheel = 480 rpm
The time in which the wheel is to be brought to rest = 40 s
The rotational rate of the wheel in rotation per second is given as follows;
480 r.p.m = 480 r.p.m × 1 minute/(60 seconds) = 8 revolution/second
1 revolution = 2·π radians
Therefore, we have the angular velocity, ω, given as follows;
ω = 2·π × 8 revolutions/second ≈ 50.3 rad/s
The angular acceleration, α, is given as follows;
[tex]\alpha = \dfrac{\Delta \omega}{\Delta t} = \dfrac{\omega _2 - \omega_1}{t_2 - t_1}[/tex]
Whereby the wheel is brought to rest from its initially constant rotational motion in 40 seconds, we have;
ω₁ ≈ 50.3 rad/s, ω₂ = 0 rad/s, and t₂ - t₁ = 40 seconds
Plugging in the values for the variables of the equation for the angular acceleration, "α", we get;
[tex]\alpha = \dfrac{0 - 50.3 \ rad/s}{40 \ s} \approx 1.3 \ rad/s^2[/tex]
The torque on the wheel, τ, is given as follows;
τ = m·r²·α
Where;
m = The mass of the object = 50 kg
r = The radius of the wheel = 0.4 m
α = The acceleration of the wheel ≈ 1.3 rad/s²
Therefore;
τ = 50 kg × (0.4 m)² × 1.3 rad/s² ≈ 10.4 N·m
The torque necessary to bring the wheel to rest in 40 seconds = τ ≈ 10.4 N·m.
Answer:
-10.048 N m
Explanation:
A student pulls a block across the desk in physics class. He applies 14N of
tension in the string, but friction holds the box back with 4N. His partner
measures the acceleration of the box across the desk to be 2m/s2. What
must the mass of the box be?
100 Pointsss hellppp
can you please show a picture
Velocities of two bodies A and B are given in vectors notation as va =i+2j-3k and Vb=3i+2j-k what will be the relative velocity of b with respect to a?
Answer:
[tex]V_{B/A}=2i+2k[/tex]
Explanation:
The relative velocity can be calculated by means of the difference between vector B minus vector A.
[tex]V_{A}=i+2j-3k\\V_{B}=3i+2j-k\\V_{B}-V_{A}=(3-1)i + (2-2)j+(-1-(-3))k\\V_{B/A}=2i+2k[/tex]
A Skydiver has a mass of 48kg, what is the force that she exerts as she is falling to the ground?
Answer:
470.4N
Explanation:
Given parameters:
Mass of the skydiver = 48kg
Unknown:
Force she exerts as she is falling to the ground = ?
Solution:
The force she exerts while falling to the ground is her weight;
Weight = mass x acceleration due to gravity
Acceleration due to gravity = 9.8m/s²
Weight = 48 x 9.8 = 470.4N
800 joules of work were done with a force of 200 newtons. Over what
distance was the force applied?
20 m
40 m
4 m
2 m
Answer:
4m
Explanation:
800/200
5
Select the correct answer.
Which statement best explains the relationship between electric force and the charges on two interacting objects?
СА.
Electrical force is directly proportional to the product of the charges on the two objects.
B.
Electrical force is inversely proportional to the product of the charges on the two objects.
Electrical force is inversely proportional to the product of the squares of the charges on the two objects.
D. Electrical force is directly proportional to the product of the squares of the charges on the two objects.
Answer:
Electrical force is directly proportional to the product of the charges on the two objects.
Explanation:
The electric force between two charges is given by :
[tex]F=\dfrac{kq_1q_2}{d^2}[/tex]
Where
k is electrostatic constant
q₁ and q₂ are charges
d is the distance between charges
It can be very clear that the electric force is directly proportional to the product of charges and inversely proportional to the square of the distance between them.
Hence, the correct option is (a) "Electrical force is directly proportional to the product of the charges on the two objects".
which property of a conducting wire is utilised in making electric fuse
Answer:
property of low melting point
Explanation:
When too much current flows through the low resistance element of the fuse, the element melts and breaks the circuit
h m u i m he ll a b o r e d
Answer:
KITTEEENNSSSSS last one is what i got for critsmas KlikBot Hexagon Special Pack
Explanation:
Q2. An initially stationary 18-kg curling rock has a force applied to it over 2.0s. Its released with a velocity of 8.3 m/s [forward]. Determine the magnitude and direction of the applied force. Try solving this problem two different ways.
Answer: 74.7 N
Explanation:
Both approaches yield the same result: the magnitude of the applied force is approximately 74.7 N, and its direction is forward.
To solve this problem, we'll use two different approaches: Newton's second law and the work-energy principle.
Approach 1: Newton's Second Law
Newton's second law states that the force applied to an object is equal to the change in momentum of the object over time.
Step 1: Calculate the initial momentum (pinitial) of the curling rock.
pinitial = m * vinitial
pinitial = 18 kg * 0 m/s (since it's initially stationary)
pinitial = 0 kg m/s
Step 2: Calculate the final momentum (pfinal) of the curling rock.
pfinal = m * vfinal
pfinal = 18 kg * 8.3 m/s
pfinal = 149.4 kg m/s
Step 3: Calculate the change in momentum (Δp).
Δp = pfinal - pinitial
Δp = 149.4 kg m/s - 0 kg m/s
Δp = 149.4 kg m/s
Step 4: Calculate the magnitude of the applied force (Fapplied).
Fapplied = Δp / Δt
Fapplied = 149.4 kg m/s / 2.0 s
Fapplied = 74.7 N
Step 5: Determine the direction of the applied force.
The direction of the applied force is forward since the curling rock is released with a velocity of 8.3 m/s forward.
So, according to Newton's second law, the magnitude of the applied force is 74.7 N, and its direction is forward.
Approach 2: Work-Energy Principle
The work-energy principle states that the work done on an object is equal to the change in its kinetic energy.
Step 1: Calculate the initial kinetic energy (KEinitial) of the curling rock.
KEinitial = 0.5 * m * [tex]vinitial^2[/tex]
KEinitial = 0.5 * 18 kg * (0 [tex]m/s)^2[/tex]
KEinitial = 0 J
Step 2: Calculate the final kinetic energy (KEfinal) of the curling rock.
KEfinal = 0.5 * m * [tex]vfinal^2[/tex]
KEfinal = 0.5 * 18 kg * (8.3 [tex]m/s)^2[/tex]
KEfinal = 0.5 * 18 kg * 69.0 [tex]m^2/s^2[/tex]
KEfinal = 621.0 J
Step 3: Calculate the work done on the curling rock (W).
W = KEfinal - KEinitial
W = 621.0 J - 0 J
W = 621.0 J
Step 4: Calculate the magnitude of the applied force (Fapplied) using the work done.
Fapplied = W / d
Fapplied = 621.0 J / 2.0 s
Fapplied = 310.5 N
Step 5: Determine the direction of the applied force.
The direction of the applied force is forward since the curling rock is released with a velocity of 8.3 m/s forward.
So, according to the work-energy principle, the magnitude of the applied force is 310.5 N, and its direction is forward.
Both approaches yield the same result: the magnitude of the applied force is approximately 74.7 N, and its direction is forward.
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Determine the force required to accelerate a 2 kilogram ball to an
acceleration of 9.8 m/s2
Answer:
19.6 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 2 × 9.8
We have the final answer as
19.6 NHope this helps you
The Periodic Table Question 3 of 10 Based on the trend in valence electrons across periods for main-group elements, how many valence electrons does fluorine (F) have? O A. 4 B. 7 O C. 6 D. 5 SUBT
Answer:
B. 7
Explanation:
Fluorine has 7 valence electrons in its orbitals.
The valence electrons are electrons in the outermost shell of an atom. Every element has a certain amount of valence electrons.
Fluorine belongs to the 7 - group on the periodic table. Every element in this group has 7 electrons in their outermost shell. The elements in the group are called halogens. Other elements in this group are fluorine, chlorine, bromine, iodine and astatine.Answer:
7
Explanation:
Which two quantities can be expressed using the same units?
1.energy and force
2.impulse and force
3.momentum and energy
4.impulse and momentum
Answer: impulse and momentum
Explanation:
Impulse and momentum- two quantities can be expressed using the same units. Hence, option (4) is correct.
What is impulse?In physics, the term "impulse" is used to characterize or measure the impact of force operating gradually to alter an object's motion. It is often stated in Newton-seconds or kilograms per second and is denoted by the symbol J.
Because a body with momentum cannot be halted, it must be forced to move in the opposite direction for a predetermined amount of time. The harder it is to stop, the more momentum there is. Consequently, more force must be applied and more time must be spent to stop the body.
Mathematically,
impulse = force· time
= mass × acceleration × time
= mass × ( change in velocity/time) × time
= mass × change in velocity
= change in momentum.
Hence, both Impulse and momentum have same unit.
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Obtain a pillow made of foam rubber. Press
down hard with your two hands on the surface
of the pillow. Then withdraw your hands
Describe what happened to its shape while you
pushed hard on the pillow and when you
withdrew your pushing. Repeat this activity on
a piece of rectangular block of wood and a
plasticine. Note the different effects.
Answer: Only foam rubber is compressible material
Explanation:
The pillow is made up of foam rubber which can be compressed easily due to the soft compressible rubber with hands on application of pressure on the surface. The shape of pillow regain its original shape when the pressure is withdrawn from the pillow. If the same activity is performed on the piece of rectangular block of wood and plasticine. Then the rectangular block of wood cannot be compressed with hand as it is a solid body. Plasticine is a putty like material. It is a clay like material and it can be compressed with hand but when the pressure is withdrawn the plasticine does not regain its shape back.
plz help asap
Which of the following techniques would be used to treat a disease based on the humoral theory?
perform a surgery
administer an enema
prescribe an antibiotic
administer a vaccine
The theory of plate tectonics explains the cause of which natural occurrence?
avalanches
floods
earthquakes
eruptions
Answer:
Given the body part: They would administer a vaccine Plate tectonics: It describes earthquakesCan someone please help?
Answer:
B
Explanation:
Speed is distance divided by time.
how is velocity ratio of wheel and axle calculated
Answer:
VR = [tex]\frac{Radius of the wheel}{Radius of the axle}[/tex]
Explanation:
Velocity ratio (VR) of a machine is a term that compares the distance moved by effort put into the machine to the distance moved by the load.
A wheel and axle is a device for lifting of a load through a height. It is made up of two circular parts called wheel and axle. Its velocity ratio (VR) can be determined by:
VR = [tex]\frac{Radius of the wheel}{Radius of the axle}[/tex]
For a practical wheel and axle, the diameter of the wheel is greater than the diameter of the axle.
When can a high speed velocity cause damage?'
Answer:
50 Mph.
Explanation:
According to the National Severe Storms Laboratory, winds can really begin to cause damage when they reach 50 mph. But here’s what happens before and after they reach that threshold, according to the Beaufort Wind Scale (showing estimated wind speeds): - at 19 to 24 mph, smaller trees begin to sway.
Please help i will give brainliest
Answer:
Answers below--
Explanation:
1. F/Force
2.H/Contact force
3.A/Non-contact force
4.C/electric force
5.D/gravity
6.I(i)/magnetic force
7.J/kilogram
8.G/newton
9.B/friction
10.E/lubricant
A bowling ball of 35.2kg, generates 218 kg.m/s units of momentum. What is the velocity of the bowling ball?
Answer:
[tex]6.18\:\mathrm{m/s}[/tex]
Explanation:
The momentum of an object is given by [tex]p=mv[/tex].
Plugging in values, we have:
[tex]218=35.2v,\\v=\frac{218}{35.2}=\fbox{$6.18\:\mathrm{m/s}$}[/tex].
Brian Berg of lowa built a house of cards 4.88 m tall. Suppose Berg throws a ball from ground level
with a velocity of 9.98 m/s straight up. What is the velocity of the ball as it first passes the top of
the card house?
Answer:
Vf = final velocity = 1.96 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}^{2}=v_{o}^{2}-2*g*x[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 9.98 [m/s]
g = gravity acceleration = 9.81 [m/s²]
x = vertical distance [m]
[tex]v_{f}^{2}=(9.98)^{2}-2*9.81*4.88\\v_{f}^{2} = 99.6-95.74\\v_{f}=\sqrt{3.8544}\\v_{f}=1.96[m/s][/tex]
Note: The negative sign of the gravity acceleration means that the gravity acceleration is pointing in the opposite direction of the movement.
1. Which of these is not a property of a soun wave? A. Elasticity B. Loudness C. Pitch
Answer:
A
Explanation:
Which identifies the energy transformations that take place in Anna’s body as this process takes place?
Mechanical energy is converted to kinetic energy, which is then converted to potential energy.
Chemical energy is converted to thermal energy and electrical energy.
Electrical energy is converted to chemical energy and thermal energy.
Mechanical energy is converted to potential energy which is then converted to kinetic energy.
Answer:
Chemical energy is converted to thermal energy and electrical energy.
Explanation:
Answer:
Which identifies the energy transformations that take place in Anna’s body as this process takes place?
Mechanical energy is converted to kinetic energy, which is then converted to potential energy.
*******Chemical energy is converted to thermal energy and electrical energy. *******CORRECT*******
Electrical energy is converted to chemical energy and thermal energy.
Mechanical energy is converted to potential energy which is then converted to kinetic energy.
Explanation:
Feb 2021 Edge 100% test
What is common between transverse waves and longitudinal waves?
Both include an amplitude, crest, and rarefactions
Both move faster at higher temperatures
Both move slower through densely packed molecules
Both include a wavelength from compression to compression
Answer:
b
Explanation:
i took the quiz
Both the transverse and longitudinal waves move faster at higher temperatures.
What is meant by transverse wave?A wave in which the motion of the particles is perpendicular to the direction of the wave propagation is referred to as a transverse wave.
Here,
As a result of the shear stress that is produced, transverse waves are frequently observed in elastic materials.
In this situation, the oscillations are caused by the displacement of the solid particles from their relaxed state in directions perpendicular to the wave's propagation.
The wave in which the particles of the medium oscillate parallel to the direction of propagation of the wave is called a longitudinal wave.
Sound waves similarly oscillate parallel to the direction of propagation, forming the compressions and rarefactions. Hence sound waves are called longitudinal waves.
Hence,
Both the transverse and longitudinal waves move faster at higher temperatures.
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PLEASE HELP!!!
Which two conditions would result in the weakest electric force between objects?
Answer:
B
Explanation:
objects are conductors with unbalanced charges
Answer:
D & A
Explanation:
An object with a mass of 2.0 kg accelerates 2.0 m/s^2. What is the amount of force acting on the object?
Answer:
Explanation:
When the mass
m
is being accelerated with an acceleration of
a
,we can say the net force acting in the direction of acceleration is
F
=
m
a
here,it is given that only one force
F
was applied to cause this acceleration, and also given,
m
=
2
K
g
,
a
=
2
m
s
−
2
So,
F
=
2
⋅
2
=
4
N
Answer:
4N
Explanation:
given formula solution
m=2kg F=ma F=2kg×2m/s^2
a=2m/s^2 =4N
Electric potential energy is the energy of a charge based on
A.
the magnitude of its charge and its position in an electric field.
B.
the magnitude of its charge, its mass, and its speed.
C.
its mass and height above a given reference point in an electric field.
D.
its speed and the direction of its motion relative to a second charge.
Answer:
EPE is the ability to provide a charge within a circuit. It can be represented as a vector quantity, which has magnitude and direction.Hence A is correctThe density of a substance is 879.26 g/mL. What is the volume of 48 g of the substance?
someone please help with this
Answer:
The new force is 2/3 of the original force
Explanation:
Coulomb's Law
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:
[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]
Where:
[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]
q1, q2 = the objects' charge
d= The distance between the objects
Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:
[tex]\displaystyle F'=k\frac{2q_1*q_2/3}{d^2}[/tex]
Factoring out 2/3:
[tex]\displaystyle F'=\frac{2}{3}k\frac{q_1*q_2}{d^2}[/tex]
Substituting the original force:
[tex]F'=\frac{2}{3}F[/tex]
The new force is 2/3 of the original force
Determine the force of gravitational attraction between the earth (m = 5.98 x 1024 kg) and a 70-kg physics student if the student is in an airplane at 40000 feet above earth's surface. This would place the student a distance of 6.39 x 106 m from earth's center.
Answer:
[tex]F=683.790939[/tex]N
Explanation:
From the Question we are told that
Earth mass [tex]m_1= 5.98 * 10^2^4 kg[/tex]
Students mass [tex]m_2=70kg[/tex]
Distance of student from earth center Radius [tex]r=6.39 * 10^6 m[/tex]
Generally the equation for Force of attraction b/w the earth and the boy is mathematically given by
[tex]F=\frac{Gm_1m_2}{r^2}[/tex]
[tex]F=\frac{6.67.10^-^1^1*( 5.98 x 10^2^4)(70)}{(6.39 *10^6)^2}[/tex]
Therefore the force of attraction b/w the student and the earth is
[tex]F=683.790939N[/tex]
[tex]F\approx 684N[/tex]
If the magnification produced by a lens has a negative value, the image will be
A) virtual and inverted
B) virtual and erect
C) real and erect
D) real and inverted
Answer:
I think it's B, not quite sure tho.