Answer:
Resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature.
Number of free electrons in a conductor remains invariant even if its temperature changes.Hence correct option is option D.
It is not possible to accurately calculate instantaneous velocity.
TRUE
FALSE
Where could we use a light bulb that has 12V written on it
Answer:
Explanation:
In a battery charger (for an auto).
As a replacement for any bulb in an auto.
As a lamp in an emergency exit where the power must be shut off.
As a light that illuminates the back of a truck, turned on when loading the truck.
a crowbar 2 metres long is used to lift a rock weighing 800 newtons .If the fulcrum is 0.25 metre,from where the bar touches the rock, how much effort must be applied to move the rock
Answer:
??
Explanation:
A steel bridge is 5.5m long. If the linear expansivity of steel is 0.000011/℃, how much will it expand when temperature rise by 10 ℃? Give your answer in cm
Answer:
The expansion of the steel bridge is 0.0605 cm
Explanation:
The given length of the steel bridge, L = 5.5 m
The linear expansivity of the steel bridge, [tex]\alpha_ L[/tex] = 0.000011/°C
The rise (change) in the temperature, ΔT = 10°C
Let, ΔL, represent the expansion of the steel bridge
Given that the linear expansivity, [tex]\alpha_ L[/tex], of a material is the change in the length of a material per unit length of the material per unit change in the temperature, we have;
[tex]\alpha_ L[/tex] = ΔL/(L × ΔT)
∴ ΔL = [tex]\alpha_ L[/tex] × L × ΔT = 0.000011 /°C × 5.5 m × 10 °C = 0.000605 meters
ΔL = 0.000605 meters
The expansion of the steel bridge, ΔL = 0.000605 meters = 0.000605 m × 100 cm/m = 0.0605 cm
Mr Chichester is driving his dark blue camaro to a REO Speedwagon concert. He is driving 15 m/s when he realizes he is going to be late to his favorite band so he slams on the gas for 10s and reaches a final velocity of 45 m/s. How far did Mr. Chichesters travel during this 10s?
Answer:
300m
Explanation:
step one
given data
initial speed u= 15m/s
final speed v= 45m/s
time taken to attain final speed= 10seconds
Step two:
Let us first solve for the acceleration
a= Δv/t
a= 45-15/10
a=30/10
a= 3m/s
applying the equation of motion
[tex]v^2=u^2+2as[/tex]
substituting our given data
[tex]45^2+15^2+2*3*s\\\\2025=225+6s\\\\[/tex]
collect like terms
2025-225=6s
1800=6s
divide both sides by 6
s=1800/6
s=300m
Pls help me!! Thank u sm
Answer:
D
Explanation:
Which example best
describes Newton's 3rd Law?
A. Paddling a canoe to make the boat move
B. A large truck takes longer to
slow down than a car
C. Falling forward in a train that is slowing down quickly
Answer:
A
Explanation:
paddling a canoe to make the boat move
An unknown material, m1 = 0.41 kg, at a temperature of T1 = 86 degrees C is added to a Dewer (an insulated container) which contains m2 = 1.7 kg of water at T2 = 22 degrees C. Water has a specific heat of cw = 4186 J/(kg⋅K). After the system comes to equilibrium the final temperature is T = 30.3 degrees C.
Complete Question
An unknown material, m1 = 0.41 kg, at a temperature of T1 = 86 degrees C is added to a Dewer (an insulated container) which contains m2 = 1.7 kg of water at T2 = 22 degrees C. Water has a specific heat of cw = 4186 J/(kg⋅K). After the system comes to equilibrium the final temperature is T = 30.3 degrees C.
Part (a) Input an expression for the specific heat of the unknown material.
Part (b) What is the specific heat in J/(kg⋅K)?
Answer:
a
[tex]c = \frac{m_2 * c_w (T - T_2)}{m_1 * (T_1 - T) }[/tex]
b
[tex]c = 2587.14 \ J /(kg \cdot K)[/tex]
Explanation:
From the question we are told that
The mass of the material is [tex]m_1 = 0.41 \ kg[/tex]
The temperature is [tex]T_1 = 86 ^oC[/tex]
The mass of water is [tex]m_2 = 1.7 \ kg[/tex]
The temperature of water is [tex]T_2 = 22^oC[/tex]
The specific heat of water is [tex]c_w = 4186 \ J/(kg\cdot K)[/tex]
The temperature of the system is [tex]T= 30 .3^o C[/tex]
Generally heat lost by the unknown material = heat gained by water
Generally the heat gained by water is mathematically represented as
[tex]Q_2= m_2 * c_w (T - T_2)[/tex]
=> [tex]Q_2= 1.7 * 4186 (30.3 - 22)[/tex]
=> [tex]Q_2= 59064.46 \ J[/tex]
Generally the heat lost by the unknown material is mathematically represented as
[tex]Q_1= m_1 * c* (T_1 - T)[/tex]
[tex]m_2 * c_w (T - T_2) = m_1 * c* (T_1 - T)[/tex]
=> [tex]c = \frac{m_2 * c_w (T - T_2)}{m_1 * (T_1 - T) }[/tex]
Here c is the specific heat capacity of the unknown material
=> [tex]Q_1= 0.41 * c (86 - 30.3)[/tex]
=> [tex]Q_1= 22.83 c[/tex]
So
[tex]59064.46 = 22.83 c[/tex]
=> [tex]c = \frac{59064.46 }{ 22.83}[/tex]
=> [tex]c = 2587.14 \ J /(kg \cdot K)[/tex]
A 0.3 kg bird flies south with a speed of 5 m/s. What is its kinetic energy?
A. 1.5 J
B. 2.5 J
C. 3.8 J
D. 8.3 J
Answer:
right answer is number C that is 3.8J since KE=1/2mv²
1.
Asthenosphere
a. the liquid layer located between the mantle and the inner
core
2.
Continental crust
b. the inner most solid layer of Earth
3.
Convection currents
the parts of Earth's crust located beneath the ocean that
make up the seafloor
4.
Crust
5.
Density
d. a transition zone beneath the lithosphere that is semi-
fluid, sometimes referred to as the plastic layer
6.
Inner core
e. the hard, rigid outermost layer of Earth
7
Lithosphere
f. all the parts of the Earth's crust that are not beneath the
ocean
8
Mantle
9.
Mesosphere
g the layer that is directly below Earth's crust and is divided
into 3 parts: lithosphere, asthenosphere, and mesosphere
h. the amount of force on a substance
10.
Oceanic crust
1. the solid lower layer of the mantle
11.
Outer core
j. the rigid, solid upper mantle connected to Earth's crust
12
Pressure
ki instrument used to measure earthquake waves
13.
Seismograph
1. the layer of Earth that is split into larger pieces: it floats on
the asthenosphere and moves due to convection currents
14.
Tectonic plates
m. the measure of mass per volume; the number of particles
in a given space
in movement of liquid and gaseous matter in a circular
motion caused by a difference in temperature; warm rises
and cool sinks, causing a circular current
Answer:
dsfghrtykuyjfcjuktj,ilyk
Explanation:
jgbnm,g bcm
What force acts on a projectile when it is launched in the air?
A. gravity
B. friction
what does the area under a speed-time graph represent
Answer: It represents the whole distance traveled. Hope this helps!
Explanation:
what is the correct answer?
Answer:
i cant explain well but the answer is letter b
x-5
Explanation:
dont report me or i will report you too
Answer:
x-5 is the answer
Explanation:
pick her as the brainliest
Cart A and B are connected by a compressed spring. Cart A has a mass of 0.8 kg and Cart B has a mass of 3.00
kg. When the spring is released, Cart B moves to the right at a speed of 4 m/s. Find the speed of Cart A.
A W
B
Answer:
?????????????????????????
given a force of 88n and an acceleration of 4m/s2 what is the mass
Answer:
The mass is 22 kilograms
Explanation:
[tex]F=ma[/tex]
[tex]88N = m(4m/s/s)[/tex]
[tex]m=\frac{88N}{4m/s^{2} }[/tex]
[tex]m=22kg[/tex]
A ball is thrown vertically upward with a speed v. An identical second ball is thrown upward with a speed of 1/2 v (half as fast). What is the ratio of the maximum height of the second ball to that of the first ball
Answer:
1:4
Explanation:
The formula for calculating the maximum height of the ball is expressed as;
H = u²sin²theta/2g
If a ball is thrown vertically upward with a speed v, its maximum height is expressed as;
H = v²sin²90/2g
Since sin90 = 1
H = v²/2g.... 1
If an identical second ball is thrown upward with a speed of 1/2 v, then the maximum height will be expressed as;
H1 = (1/2v)²sin²90/2g
H1 = (v²/4)(1)/2g
H1 = v²/8g ...... 2
Divide both equations
H/H1 = (v²/2g)/(v²/8g)
H/H1 = v²/2g × 8g/v²
H/H1 = 8g/2g
H/H1 = 4
Reciprocate both sides
H1/H = 1/4
H1:H = 1:4
Hence the ratio of the maximum height of the second ball to that of the first ball is 1:4
Clarissa has a credit card with a limit of $1,000 and pays her balance in full each month. If Clarissa needs a short-term loan, can she use her credit card as collateral at a pawn shop? Why or why not? Select the best answer from the choices provided. A. She cannot use it because a credit card is not collateral. B. If the balance on the credit card is zero, she can use it. C. If the balance on the credit card is $1,000, she cannot use it. D. She can use it if she increases the credit limit.
Answer:
B.she cannot use it because the credit card is not collareral
Explanation:
sorry if am wrong
An object is placed 5 cm away from a lens of magnification 3.2.
How far away from the lens is the image formed?
Answer:
16 cm
Explanation:
Magnification (M)= v/u
where V = image distance from lens
u = object distance from lens
Given that the object is 5 cm away from the lens
The magnification of the lens is 3.2
image distance from lens (v) = magnification * object distance = 3.2 * 5 =16cm
What is the frequency of a wave with a wavelength of 2 and velocity of 20m/s?
Answer:
I think it is 10 Hz
Explanation:
Sorry if it's wrong
Why is it difficult to use the law of conservation of energy to calculate the
effects of a collision?
Answer:
B
Explanation:
In a collision some of the kinetic energy of the object convert into thermal energy and sound. It's not so easy to measure thermal and sound energy. That's why it's difficult to use law of conservation of energy.
Alert: Energy is always conserved.
Ya sabes que los materiales se utilizan dependiendo de la fun- ción que deben tener: transparentes (cristales), conductores de la electricidad (cables de tendidos eléctricos), muy resistentes (vigas), inoxidables (cuberterías), etc. Pero, ¿interesarán materiales de densidad grande o pequeña? ¿Por qué? Busca ejemplos de tres materiales que justifiquen tu respuesta (por ejemplo, el hilo conductor de las líneas de alta tensión, los colchones de espuma de alta densidad, la fibra de carbono, etc). ¿Qué características tiene la fibra de carbono en cuanto a resis- tencia y densidad? Busca objetos que se elaboren con fibra de carbono.
say something random cuz i already answered my own question
Answer:
The experimental setup, with car 1 is at the top of a ramp and car 2 at the bottom of the ramp is explained below in details.
Explanation:
The meter pole should be located at the opening location of car second at the bottom of the ramp so that it regulates the portion of car second that will finish up the most distant away from the bottom of the ramp.
So, I think now you got your answer which is absolutely correct and it will help you.
Answer:
hello my good friend
Explanation:
Which has greater kinetic energy: a bowling ball that has a mass of 5 kg travelling at 6 m/s, or a ship that has a mass of 120000 kg and is moving at 0.02 m/s?
Answer:
The bowling ball has greater kinetic energy.
Explanation:
Kinetic energy is given by:
[tex] K = \frac{1}{2}mv^{2} [/tex]
Where:
m: is the mass
v: is the speed
For the bowling ball we have:
[tex]K = \frac{1}{2}mv^{2} = \frac{1}{2}5 kg*(6 m/s)^{2} = 90 J[/tex]
And for the ship:
[tex]K = \frac{1}{2}mv^{2} = \frac{1}{2}120000 kg*(0.02 m/s)^{2} = 24 J[/tex]
Therefore, the bowling ball has greater kinetic energy.
I hope it helps you!
You’ve been in a car traveling at 80 km/hr. How many hours will it take to travel 640 km?
How many kilometers in 487,320 meters? If there are 1,000 meters in one kilometer?
Answer:
48.732
Explanation:
Just move the denominator 3 times for the 0s in 1000.
No machine have 100% efficiency. Why?
[tex]\huge\fcolorbox{black}{pink}{Answer}[/tex]
Because said machines have to operate in the physical world with constraints caused by the laws of physics. It’s not possible to do useful work without encountering some of these issues. The mains ones are:
Heat lost from the systemFriction (including air resistance)Electrical resistance[tex]\sf\blue{hope\:it\:helps}[/tex]
a student tries to produce notes of higher frequency by blowing a trumpet harder. he will succeed?
Answer:
Please mark as Brainliest!!
Explanation:
He will not succeed as it blows the trumpet harder that only increase the amplitude of the sound wave that means the intensity of the sound will increase but the frequency remains the same.
Answer:
he wont
Explanation:
Water boiling
Which one is shown? (Look at pic)
Answer:
conduction.
Explanation:
Hoped I helped! Im Eve btw have a great day and consider marking this brainliest if you do thank you in advanced!
A feather is falling towards the ground at a constant speed. Of the forces listed, identify which act upon the feather.
Answer:
Gravitational force
Explanation:
Gravitational force is what is making the feather go down. It's pushing the feather down, without the Gravitational force, the feather would have been going up, and not down. Just like us. Gravitational force is what keeps us humans from floating ( unless ur an alien jklol), So yeah Gravitational force is the force that acts upon the feather to fall towards the ground at a constant speed.
Btw, u never listed the forces here just ....
Hope this helped!
A feather is falling towards the ground at a constant speed. Forces act upon the feather is gravitational force.
What is force?
A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
When body is falling the net acceleration that objects get as a result of the combined action of gravity and centrifugal force is known as the Earth's gravity, or g. It is a vector quantity
A feather is falling towards the ground at a constant speed. Forces act upon the feather is gravitational force.
To learn more about force refer to the link:
brainly.com/question/13191643
#SPJ2
Calculate the time needed to drive a car 100 kilometers if the car is traveling at a speed of 70 km/hr.
A.14 hours
B. 7 hours
C. .7 hours
D.1.4 hours
Answer:
D.1.4 hours
Explanation:
[tex]d\ =\ vt[/tex]
[tex]t\ =\ \frac{d}{v}[/tex]
[tex]t\ =\ \frac{100}{70}[/tex]
[tex]t\ =\ 1.42857142857[/tex]
Therefore, the answer is D 1.4 hours