Answer:
Walking –We can walk only if we apply frictional force. Friction is what holds your shoe to the ground. The friction present on the ice is very little, this is the reason why it is hard to walk on the slippery surface of the ice.
Writing – A frictional force is created when the tip of the pen comes in contact with the surface of the paper. Rolling friction is what comes into play while writing with a ballpoint pen while sliding friction arises when one writes with a pencil.
Skating – A thin film of water under the blade is necessary to make the skate slide. The heat generated by the skate blade rubbing against the surface of ice causes some of the ice to melt right below the blade where the skater glides over the ice. This water acts as a lubricant reducing friction.
Lighting a matchstick – When the head of the matchstick is rubbed against a rough surface, heat is generated and this heat converts red phosphorous to white phosphorous. White phosphorous is highly inflammable and the match stick ignites. Sometimes, matchsticks fail to ignite due to the presence of water. Water lowers friction.
Driving of the vehicle on a surface- While driving a vehicle, the engine generates a force on the driving wheels. This force initiates the vehicle to move forwards. Friction is the force that opposes the tyre rubber from sliding on the road surface. This friction avoids skidding of vehicles.
Applications of breaks in the vehicle to stop it- Friction braking is the most widely used braking method in vehicles. This process involves the conversion of kinetic energy to thermal energy by applying friction to the moving parts of a vehicle. The friction force resists the motion and in turn, generates heat. This conversion of energy eventually bringing the velocity to zero.
Flight of aeroplanes- Drag is the force that opposes the forward motion of the aeroplane. The friction which resists the motion of an object moving through a fluid or immobile in a moving fluid, as occurs when we fly a kite. The friction of the air is created as it meets and passes over an aeroplane and its components. Drag is generated by air impact force, skin friction and displacement of the air.
Drilling a nail into the wall- Friction is responsible for fixing of nails in a wall. As the nail is driven into the wall, the nearby material to the nail of the wall gets compressed. This exerts a force on the nail. This force is the friction that converts the normal force exerted by the compressed layers of the wall into the resisting shear force. In this manner the friction cause nails and screws to hold on to walls.
The dusting of the carpet by beating it with a stick- When the carpet is beaten with the stick, the dust comes out. The dust is carried off by the wind or falls on the floor. The carpet exhibits a little static friction that holds the dust to the carpet. When the carpet is beaten, it will overcome the friction and the carpet will move away from the dust making the carpet free from dust.
Sliding on a garden slide- We know that friction is a force that is present whenever two objects rub against each other. In case of a slide in the garden such as a slide and a person’s backside rub each other’s surface. Without friction, a slide would accelerate the rider too quickly, resulting in possible injury due to the fall. The friction reduces the velocity of the sliding person and makes him stop.
Hope that helps! :D Sorry if it's too lengthy...
Explanation:
- Atoms of different elements:
(a) Have the same atomic heat capacity.
(b) Have the same specific heat.
(c) Have the same heat capacity.
mention the characteristics of small scale business(any5)
Explanation:
plzzzz mark me brainliest if it helps you then
A marble at the front of a truck bed traveling at 20 m/s relative to the highway rolls toward the back of the truck bed with a speed of 7m/s relative to the truck bed. What is the velocity of the marble relative to the highway?
4. If the cooling of magma takes place slowly beneath Earth's surface, the rock is that is formed
is called
a. extrusive igneous rock
b. intrusive igneous rock
c. sedimentary rock
d. metamorphic rock
An important news announcement is transmitted by radio waves to people who are 46 km away, sitting next to their radios, and by sound waves to people sitting across the newsroom, 2.1 m from the newscaster. Take the speed of sound in air to be 348 m/s. What is the difference in time that the message is received
Answer:
[tex]0.005847\ \text{s}[/tex]
Explanation:
Radio waves travel at the speed of light
[tex]c[/tex] = Speed of light = [tex]3\times 10^8\ \text{m/s}[/tex]
[tex]d_r[/tex] = Distance between two radios = 46 km
[tex]v[/tex] = Speed of sound in air = 348 m/s
[tex]d_s[/tex] = Distance sound travels across the newsroom = 2.1 m
Time taken by the radio signal to reach the required location is
[tex]t_r=\dfrac{d_r}{c}\\\Rightarrow t_r=\dfrac{46\times 10^3}{3\times 10^8}\\\Rightarrow t_r=0.000153\ \text{s}[/tex]
Time taken by sound to reach the required location is
[tex]t_s=\dfrac{d_s}{v}\\\Rightarrow t_s=\dfrac{2.1}{348}\\\Rightarrow t_s=0.006\ \text{s}[/tex]
The time difference is
[tex]t_s-t_r=0.006-0.000153=0.005847\ \text{s}[/tex]
The difference in time that the message is received is [tex]0.005847\ \text{s}[/tex].
A crude oil storage tank initially contains 1000 of crude oil. Oil is pumped into the tank through a pipe at a rate of 2 and out of the tank at a velocity of 1.5 m/s through another pipe having a diameter of 0.15m. The crude oil has a specific volume of 0.0015 . Determine:a) The mass of oil in the tank, in kg, after 24 hoursb) The volume of oil in the tank, in , at that time
This question is incomplete, the complete question is;
A crude oil storage tank initially contains 1000 m³ of crude oil. Oil is pumped into the tank through a pipe at a rate of 2 m³/min and out of the tank at a velocity of 1.5 m/s through another pipe having a diameter of 0.15m. The crude oil has a specific volume of 0.0015 m³/kg .
Determine : a) The mass of oil in the tank, in kg, after 24 hours b) The volume of oil in the tank, in m³, at that time ( after 24hrs )
Answer:
a) The mass of oil in the tank after 24hrs is 1059852.6667 kg
b) The volume of oil in the tank, in m³, at that time is 1589.779 m³
Explanation:
Given that;
volume of tank v = 1000 m³
Discharge (AV)₁ = 2 m³/min
specific volume (v) = 0.0015 m³/kg
a)
for one inlet, one exit control volume, we have]
d(mc[tex]_v[/tex])/dt = "m[tex]_i[/tex] - "m[tex]_e[/tex]
"m[tex]_i[/tex] = (AV)₁ / v
"m[tex]_i[/tex] = 2 / 0.0015
"m[tex]_i[/tex] = 1333.33 kg/min = ( 1333.33 kg/min × 60 ) = 80,000 kg/hr
"m[tex]_e[/tex] = AV₂/v
AREA A = πr² = π(0.15m/2)²
so
"m[tex]_e[/tex] = ( π(0.15m/2)² × 1.5 m/s ) / 0.0015m³/kg
"m[tex]_e[/tex] = 17.6714 kg/s = (17.6714 kg/s × 60 × 60 ) = 63,617.25 kg/hr
d(m[tex]_{cv}[/tex])/dt = 80000 - 63,617.25 = 16382.75 kg/hr
now after 24 hours, the mass of the crude oil tank is;
mc[tex]_v[/tex]( 24 ) = ( 16382.75 × 24 ) + mass initially contained
so initial mass m[tex]_i[/tex] = volume / specific volume
initial mass m[tex]_i[/tex] = V / v = 1000 / 0.0015 = 666,666.6667 kg
Total mass = m[tex]_i[/tex] + mc[tex]_v[/tex]
Total mass = 666,666.6667 kg + (16382.75 × 24)
Total mass = 1059852.6667 kg
Therefore, The mass of oil in the tank after 24hrs is 1059852.6667 kg
b)
Volume will be;
V = total mass × density
V = 1059852.6667 kg × 0.0015 m³/kg
V = 1589.779 m³
Therefore, The volume of oil in the tank, in m³, at that time is 1589.779 m³
(WILL MARK BRAINLIAST)( 1 answer question.. look the photo)
As the cars come closer together, the amount of potential energy in the system:
-Increases
-Decreases
-Stays the same
Answer:
increases
Explanation:
due to less speed
An instrument that produces an electric current in the presence of
a radioactive substance is called a
a. particle accelerator.
b. Geiger counter.
c. cloud chamber.
d. bubble chamber.
Answer:
Option B, Geiger counter
Explanation:
Air plane travels 224 in 2 hours.
How fast was the plane traveling?
Answer:
112mph
Explanation:bugyg
I need help with 5 please and thank you
Answer: A
Explanation:
Which water on earth is the largest,second to the largest,3rd to the largest,fourth to the largest and 5th to the largest?
Answer:
Explanation:
There are a total of 5 differen classification for the types of bodies of water that exist on Earth. These 5 would be the following: Oceans, seas, lakes, rivers, and canals. Oceans are the biggest bodies of water on Earth. If we ranked them by their size the ranking would be the following...
Pacific Ocean - being 155,556,651 sq km. in size
Atlantic Ocean - being 76,761,938 sq km. in size
Indian Ocean - being 68,555,923 sq km. in size
Antarctic / Southern Ocean - being 20,327,001 sq km. in size
Arctic Ocean - being 14,055,930 sq km. in size
NEED HELP ASAP!!!
-The difference between chemical reactions and nuclear reactions
-The difference between fission and fusion
-What is given off during nuclear decay (how elements change into others)
-How to calculate half life or amount of sample left from half life
Explanation:
Chem has to do with stored energy while nucleic deals with nucleic reactions.
diffused reflection occurs if a ray of light is reflected by a
Answer:
Diffused reflection occurs if ray of light is reflected by rough surface
what is the reason for timing more than one oscillation in a simple pendulum
Answer:
Time period is the time taken by the body to complete one oscillation and it is noted more than once to get accurate reading from averaging of all the observed values.
When the frequency of a sound wave is doubled, then:
Answer:
If the frequency of a wave is doubled, what happens to its wavelength? If the frequency is doubled, the wavelength is only half as long.
Hey,
QUESTION)✔ We have : λ = v/f
According to this relationship, the wavelength is inversely proportional to the frequency. So when the frequency doubles, the wavelength is halved.
12. A baseball (m = 0.14 kg) with initial velocity of -40 m/s (90 mph) is hit. It leaves the bat with a velocity of 60m/s after 0.001s. What is the impulse and average net force applied to the ball by the bat?
Answer:
the impulse is 14 kg-m/s and the net force applied is 14000 N
Explanation:
Given that,
The mass of a baseball, m = 0.14 kg
Initial velocity of the baseball, u = -40 m/s
Final velocity, v = 60 m/s
Time, t = 0.001 s
We need to find the impulse and average net force applied to the ball by the bat.
Impulse = change in momentum
i.e.
J = m(v-u)
J = 0.14 × (60-(-40))
J = 14 kg-m/s
Now,
J = Ft
F is average force applied to the ball
So,
[tex]F=\dfrac{J}{t}\\\\F=\dfrac{14}{0.001}\\\\F=14000\ N[/tex]
So, the impulse is 14 kg-m/s and the net force applied is 14000 N.
Assume a uniformly charged ring of radius R and charge Q produces an electric field Ering at a point P on its axis, at distance x away from the center of the ring. Now the charge Q is spread uniformly over the circular area the ring encloses, forming a flat disk of charge with the same radius. How does the field Edisk produced by the disk at P compare to the field produced by the ring at the same point?Assume a uniformly charged ring of radius R and charge Q produces an electric field Ering at a point P on its axis, at distance x away from the center of the ring. Now the charge Q is spread uniformly over the circular area the ring encloses, forming a flat disk of charge with the same radius. How does the field Edisk produced by the disk at P compare to the field produced by the ring at the same point?
Answer:
* E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
*E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
Explanation:
Let's start by finding the electric field of the charged ring
in the attachment we can see a diagram of the system. Due to circular symmetry, the electric field perpendicular to the axis is canceled and only the electric field remains parallel to the axis.
Eₓ = E cos θ (1)
E = k ∫ [tex]\frac{dq}{r^2}[/tex]
cos θ = x / r
using the Pythagorean theorem
r = [tex]\sqrt{x^2 + y^2}[/tex]
we substitute
Eₓ = k ∫ [tex]\frac{dq}{x^2+y^2} \ \frac{x}{\sqrt{ x^2+y^2} }[/tex]
Eₓ = [tex]k \frac{x}{(c^2+y^2)^{3/2} }[/tex] ∫ dq
Eₓ = k \frac{x}{(c^2+y^2)^{3/2} } Q
the ring's electric field
E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
Now let's find the electric field of the disk
The charge is distributed over the entire disk, so let's use the concept of charge density
σ = [tex]\frac{dq}{dA}[/tex]
Let's approximate the disk as a group of rings, the width of each ring is dr, the area is
dA = 2πr dr
we substitute
σ = [tex]\frac{1}{2\pi r} \ \frac{dq}{dr}[/tex]
dq = 2π σ r dr
we substitute in equation 1, where the electrioc field is of each ring
Eₓ = [tex]k \int\limits^R_0 \ { \frac{x}{(x^2+r^2)^{3/2} } \ 2\pi \sigma \ r } \, dr[/tex]
if we use a change of variable
dv = 2rdr
v = r²
Eₓ = [tex]k x \pi \sigma \int\limits^a_b { \frac{1}{(x^2+v)^{3/2} } } \, dv[/tex]
we integrate
Eₓ = k x π σ [tex][ \frac{ (x^2 + r^2)^{-1/2} }{-1/2} ][/tex]
we value in the limits from r = 0 to r = R
Eₓ = k π σ x (-2) [ [tex]\frac{1}{ \sqrt{x^2+R^2} } - \frac{1}{x}[/tex]]
Eₓ = 2π k σ ([tex]1 - \frac{x}{(x^2 + R^2 ) ^{1/2} }[/tex] )
σ = Q/πR²
substitute
Eₓ = 2 k Q/R² (1 - \frac{x}{(x^2 + R^2 ) ^{1/2} } )
E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
The two electric fields are
* E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
*E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
we can see that the functional relationship of the two fields is different
What instrument makes the slowest vibration? A drum? A whistle? A flute? Or a harmonica?
Answer:
A harmonica.
Explanation:
The structure of a harmonica is built in such a way that when the air is blown by the player in it, the air moves within the rectangular structure and making sound vibrations. Sound is heard when an object vibrates. The movement of this vibration creates sound waves, and these waves enter our ears in the form of music.
Therefore, the instrument that will make the slowest vibration among the given instrument will be the harmonica. Thus option D is correct.
A stone with a mass of 0.600 kg is attached to one end of a string 0.900 m long. The string will break if its tension exceeds 50.0 N. The stone is whirled in a horizontal circle on a frictionless tabletop; the other end of the string remains fixed.
A. Draw a free-body diagram of the stone.
B. Find the maximum speed the stone can attain without breaking the string.
Answer:
8.7 m/s
Explanation:
Given data
Mass= 0.6kg
radius= 0.9m
Force= 50N
A. Please see attached the FBD of the stone
B. Apply the formula
F= mv^2/r
Substitute
50= 0.6*v^2/0.9
cross multiply
50*0.9= 0.6v^2
45= 0.6v^2
v^2= 45/0.6
v^2= 75
v= √75
v= 8.7 m/s
Hence the maximum speed attained without breaking the string is 8.7 m/s
Which of the following is an example of the transformation of gravitational potential energy into motion energy (kinetic energy)?
Answer:
c
Explanation:
because a drop of water is falling and that is gravitational potential energy into motion energy
5. It takes
to get a job done.
Answer:
determination
Explanation:
The statement "If a plant receives fertilizer,
then it will grow to be bigger than a plant
that does not receive fertilizer" is an
example of
A. an observation.
B. a hypothesis.
C. a theory.
During a lab experiment, a student took his resting pulse rate, counting 25 beats in 20 seconds. What was the student's pulse rate in beats per minutes (bpm)?
Answer:
75 bpm
Explanation:
60 seconds in a minute
60seconds / 20 seconds = 3
25 beats * 3 = 75 bpm
Which of the following is an example of an ascribed status?
Multiple Choice
1. musician
2. poor
3. female
4. college student
From the given options the best example of an ascribed status will be poor. Hence, option 2 is the correct one.
What is ascribed status?In sociology, the term "ascribed status" refers to a human's social standing as it is either allocated to them at birth or implicitly assumed in later life. The position of status is one that a person neither chooses for themselves nor earns. Instead, the position is decided upon in accordance with cultural and societal norms and standards. No matter how hard you try or how much you want to, these slots are filled. These fixed social designators are independent of the favorable or unfavorable stereotypes associated with one's assigned statuses and stay unchanged throughout a person's life.
Every society engages in the process of classifying people into categories based on factors including gender, race, family history, and ethnicity. This process is cross-cultural.
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What happens in the inner ear
The inner ear has two special jobs. It changes sound waves to electrical signals (nerve impulses). This allows the brain to hear and understand sounds. The inner ear is also important for balance.
hope this helped :)
Answer:
Hope this helps ヾ(⌐■_■)ノ♪
Explanation:
Once the vibrations of the eardrum have been transmitted to the oval window, the sound waves continue their journey into the internal ear. The parts of the inner ear have very important purposes for your hearing and your balance.
.
describe how electrons create electricity
describe how electrons create electricity
Atoms are made up of even smaller elements, called protons, electrons and neutrons. When electrical and magnetic forces move electrons from one atom to another, an electrical current is formed
Electrons in atoms can act as our charge carrier, because every electron carries a negative charge. If we can free an electron from an atom and force it to move, we can create electricity. ... In its balanced state, copper has 29 protons in its nucleus and an equal number of electrons orbiting around it.
Hope It Helps!
a box is at rest on a slope
Answer:
170 N
Explanation:
The following data were obtained from the question:
Mass (m) = 20 Kg
Angle (θ) = 30°
Acceleration due to gravity (g) = 9.8 m/s²
Weight (W) =?
The perpendicular component of the weight can be obtained by using the following formula:
W = mg × Cosθ
W = 20 × 9.8 × Cos 30
W = 196 × 0.866
W = 169.7 ≈ 170 N
Therefore, perpendicular component of the weight is 170 N
a girl runs and cover a distance of 200m in 20 secends.The speed of the girl is ................ m/s.
Speed = distance/time
Speed = (200m)/(20s)
Speed = 10 m/s
A human body consists of
Answer:
60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Explanation:
How many atoms are in one mole of uranium?
A. 6.02 x 10^-23
B. Avogadro's number
C. 6.02 x 10^24
D. 6,020,000,000,000,000,000,000,000
Answer:
A
Explanation:
6.02×10^23 hope this helps
According to Avogadro's constant, 1 mole of uranium-235 will contain 6.022×10⁻²³ atoms of uranium-235 (option-A).
What is a mole of uranium?A mole of any element has an atomic mass on the Periodic Table that is equal to its mass in grams. A mole of uranium weighs 238.03 grams.
The atomic structure of uranium has 92 protons and 92 electrons, as indicated by its atomic number of 92. The nucleus of U-238 contains 146 neutrons, but this number can range from 141 to 146.
12 grams of pure carbon-12 weigh exactly one mole, or 6.022 x 1023 atoms, making one mole equivalent to 12 grams of pure carbon-12. • Avogadro's Number is the quantity of particles included in one mole (6.0221421 x 10⁻²³).
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