Answer:
The catcher does negative work on the ball because the force exerted by the catcher is opposite in direction to the motion of the ball.
Explanation:
what is the magnitude of electric field at apoint 2 meter from a point charge q= 4nc
Match the following items.
1. Extremely small building blocks of matter.
2. Forming new matter from old matter.
3. Small bits of matter.
atom
molecule
chemical change
Marcy pulls a backpack on a wheels down the 100m hall. The 60N force is applied at an angle of 30° above the horizontal. How much work is done by Marcy?
Answer:
Work= Fcos∆×S
W=60N×cos 30⁰×100
W=60×0.866×100=5196.1J
PLEASE GIVE BRAINLIEST
A diagram of a plant cell is shown below.
Which organelle is found in both plant and animal cells?
Cell membrane
Chloroplast
Ο Ο Ο
Large Vacuole
Cell Wall
Answer:
The Cell Membrane is found in both plant and animal cells.
Explanation:
Chloroplast, Large Vacuole and Cell Wall are all found in plant cells.
Your heart pumps blood into your aorta (diameter 2.5 cm) with a maximum flow rate of about 500 cm^3/s. Assume that blood flow in the aorta is laminar (which is not a very accurate assumption) and that blood is a Newtonian fluid with a viscosity similar to that of water.
a. Find the pressure drop per unit length along the aorta. Compare the pressure drop along a 10 cm length of aorta to atmospheric pressure (105 Pa).
b. Estimate the power required for the heart to push blood along a 10 cm length of aorta, and compare to the basal metabolic rate of 100 W.
c. Determine and sketch the velocity profile across the aorta (assuming laminar flow). What is the velocity at the center
Answer:
a. i) The pressure drop per unit length is 52,151.89 Pa
ii) The atmospheric pressure ≈ 19.175 × The pressure drop along 10 cm length of aorta
b i) The power required for the heart to push blood along a 10 cm length of aorta, is 2.6075945 Watts
ii) The basal metabolic rate ≈ 38.35 × The power to push the blood along a 10 cm length of aorta
c. i) Please find attached the drawing for the velocity profile created with Microsoft Excel
ii) The velocity at the center is approximately 2.04 m/s
Explanation:
The given diameter of the aorta, D = 2.5 cm = 0.025 m
The maximum flow rate, Q = 500 cm³/s = 0.0005 m³/s
Assumptions;
The blood flow is laminar
The blood is a Newtonian fluid
The viscosity of water ≈ 0.01 poise = 1 cp
a. i) The pressure drop per unit length of pipe ΔP/L is given by the Hagen Poiseuille equation as follows;
[tex]Q = \dfrac{\pi \cdot R^4}{8 \cdot \mu} \cdot \left(\dfrac{\Delta p}{L} \right)[/tex]
Where;
Q = The flow rate = A·v
A = The cross sectional area
R = The radius = D/2
Δp/L = The pressure drop per unit length of the pipe
Therefore, we have;
[tex]\dfrac{\Delta p}{L} = \dfrac{Q\cdot 8 \cdot \mu }{\pi \cdot R^4} = \dfrac{0.0005 \times 8 \times 1}{\pi \times 0.0125^4 } = 52151.89[/tex]
The pressure drop per unit length ΔP/L = 52,151.89 Pa
ii) The pressure, ΔP, drop along 10 cm (0.1 m) length of aorta = ΔP/L × x;
∴ ΔP = 52,151.89 Pa × 0.1 m = 5,215.189 Pa
Given that the atmospheric pressure, [tex]P_{atm}[/tex] = 10⁵ Pa, we have;
[tex]P_{atm}[/tex]/ΔP = 10⁵/5,215.189 ≈ 19.175
Therefore, the atmospheric pressure is approximately 19.175 times the pressure drop along 10 cm length of aorta
b. i) The power, P = Q × ΔP
Therefore, the power required for the heart to push blood along a 10 cm length of aorta, is P₁₀ = 0.0005 m³/s × 5,215.189 Pa = 2.6075945 Watts
ii) Therefore compared to the basal metabolic rate of, 'P', 100 W, we have;
P/P₁₀ = 100 W/2.6075945 Watts = 38.349521 ≈ 38.35
The basal metabolic rate is approximately 38.35 times more powerful than the power to push the blood along a 10 cm length
c. i) The velocity profile across the aorta is given as follows;
[tex]v_m = \dfrac{1}{4 \cdot \mu} \cdot \dfrac{\Delta P}{L} \cdot R^2[/tex]
Where;
[tex]v_m[/tex] = The velocity at the center
We get;
[tex]v_m = \dfrac{1}{4 \times 1} \times 52,151.89 \times 0.0125^2 \approx 2 .04[/tex]
The velocity at the center, [tex]v_m[/tex] ≈ 2.04 m/s
ii) The velocity profile, v(r), is given by the following formula;
[tex]v(r) = v_m \cdot \left[1 - \dfrac{r^2}{R^2} \right][/tex]
Therefore, we have;
[tex]v(r) = 2.04 - \dfrac{2.04 \cdot r^2}{0.0125^2} \right] = 2.04 - 163\cdot r^2[/tex]
The velocity profile of the pipe is created with Microsoft Excel
If an engine cannot be 100%
efficient, what happens to the
energy that is lost?
A. It disappears.
B. It reproduces.
C. It still exists, but in a different form.
Answer: Given the evidence in the explanation, I'm pretty sure it's C. It still exists, but in a different form.
Explanation: "Some part of the energy supplied is used to change the internal energy of the system. Some part is also released into the surroundings. Generally, frictional losses are more predominant for the machines being not 100% efficient. This friction leads to the loss of energy in the form of heat, into the surroundings."
Outline 3 disadvantages and advantage of water and alcohol as a template liquid
Answer:
Advantages of mercury as a thermometric liquid.
-It is a good conductor of heat and therefore the whole liquid reaches the temperature of the surroundings quickly.
-It does not wet (cling to the sides of) the tube.
-It has a high boiling point
-It expands uniformly (linear expansion) and responds quickly to temperature changes, hence is sensitive.
-It has a visible meniscus.
Disadvantages
-Mercury is very poisonous.
-its expansively is fairly low
-it is expensive
-It has a high freezing point therefore it cannot be used in places where the temperature gets very low.
Alcohol has a thermometric fluid
-Alcohol expands uniformly.
-It has a low freezing point (-115 degreecentigrade) therefore it is very suitable for place where the temperature gets very low.
-It has a large expansively
-It is an easily available cheap liquid, which is safe to use
Disadvantages of alcohol
-it wets the tube
-it has a low boiling point (cannot be used in places with high temperatures)
-it does not react quickly to changes in temperature
-It needs to be dyed, since it's colourless.
Disadvantages of water
-Water has high specific heat capacity. So it cannot be used for measuring small temperature differences.
- Water will wet the surface of the glass tube. It is a sticky substance.
- Water is transparent
Explanation:
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].
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
In fatal crashes, more than __________% of passenger car occupants who were totally ejected from the vehicle were killed.
Answer:
it would be 83% in a fatal crash.
Use the drop-down menus to complete the sentences.
A concave lens is
in the middle than at the edges, and causes light rays to
A convex lens is
in the middle than at the edges, and causes light rays to
Answer:
1) thinner, diverge
2) thicker, converge
Explanation:
i got it right thanks to the other user :)
A concave lens is thinner in the middle than at the edges, and causes light rays to diverge.
A convex lens is thicker in the middle than at the edges, and causes light rays to converge.
What are concave and convex lens?The lenses used to form images of the object placed a distant apart.
The concave mirror form images by virtual meeting of the light rays and appear to meet. They are thin at the middle portion.
The convex mirror form images by real meeting of the light rays. They converge the rays coming from object. They are thick at the middle portion.
Thus, A concave lens is thinner in the middle than at the edges, and causes light rays to diverge.
A convex lens is thicker in the middle than at the edges, and causes light rays to converge.
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The National Institute of Health is testing sensors which measure the energy felt by goalkeepers when blocking soccer balls coming at them and the velocity of soccer balls. One sensor measuring velocity is inside a 16 ounce soccer ball, which is kicked by a player at an initial velocity of 31 m/s. The ball bounces off the goalkeeper at a final velocity of 2.25 m/s. How much energy in Joules should the sensor say the goalkeeper absorbed, not accounting for wind and drag
Answer:
E = 216.76 J
Explanation:
The amount of energy absorbed by the goalkeeper will be equal to the difference between the initial and the final kinetic energy of the ball.
[tex]Energy\ Absorbed = Initial\ Kinetic\ Energy - Final\ Kinetic\ Energy\\Energy\ Absorbed = E = \frac{1}{2}mv_{i}^2 - \frac{1}{2}mv_{f}^2\\E = \frac{1}{2}m(v_{i}^2 - v_{f}^2)\\[/tex]
where,
m = mass of ball = (16 ounce)(0.0283495 kg/1 ounce) = 0.4535 kg
vf = final velocity = 2.25 m/s
vi = initial velocity = 31 m/s
Therefore,
[tex]E = \frac{1}{2}(0.4535\ kg)[(31\ m/s)^2 - (2.25\ m/s)^2][/tex]
E = 216.76 J
An 80 N force causes a spring to compress 0.15 m. What is the spring constant? What is the potential energy of the spring?
The spring constant of the given spring is= -533.33
The potential energy of the spring= 6 Joule
What is force?
A push or pull that causes object to change its state of rest or motion.
It can also change the direction of a moving body.Force is a product of mass and acceleration.For spring;
K is the spring constant.
⇒Force = -kx
⇒80N=0.15m ×-k
⇒K=-80/0.15
⇒K= -533.333
So the spring constant is 533.333
Potential Energy=1/2kx²
⇒0.5×533.33 ×0.15×0.15
⇒5.95.99 N
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27. The electric field around a positive charge is shown in the diagram. Describe the nature of these lines. Please use 2 content related sentences
Answer:
Once we place a positive test at a point close to the sphere, we find that an electrostatic force is applied to the outside of the sphere. Therefore, at any point around the sphere, the electric field vector is radially outward.
PLEASE HELP
The spine is part of which system?
A. Circulatory System
B. Central Nervous System
C. Endocrine System
Answer:
Explanation:
B. Central Nervous System
Which of these is NOT a form of energy?
A. mechanical
B. chemical
C. theoretical
D. thermal
Answer:
I think it's theoretical.
27. The traffic officer issued violation tickets to traffic
violators. If 68 of them composed 80% of the total
violators, how many violators are there in all?
A. 83
B. 84
C. 85
D. 86
28. There are 18 roses in a bunch of 24 flowers.
What percent of the flowers are roses?
A. 18%
B. 24% C. 60% D. 75%
Please help me ❤️❤️ thank u
Hope god
Answer:
27: 85
28:75%
Explanation:
27:68=80
?=100 hence (68×100)÷80
=85
28:18/24× 100
=75%
A child swings with a small amplitude on a playground with a 2.5m long chain.
a) what is the period of the child’s motion
b) what is the frequency of vibration
a. The period of the child's motion is 3.171 seconds.
b. The frequency of the vibration is 0.315 Hz.
Calculation of the period & frequency:Since A child swings with a small amplitude on a playground with a 2.5m long chain.
a. So here the time period should be
[tex]2\times \ pi(L/g)^{1/2}\\\\2\times 3.14(2.5/9.81)^{1/2}[/tex]
T=3.171s
b) Now the frequency is
[tex]T=1\div f\\\\f=1\div 3.171[/tex]
f=0.315Hz
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Noah Formula is riding an old-fashioned roller coaster. Noah encounters a small hill having a radius of curvature of 12.0 m. At the crest of the hill, Noah is lifted off his seat and held in the car by the safety bar. If Noah is traveling with a speed of 14.0 m/s, then use Newton's second law to determine the force applied by the safety bar upon Noah's 80-kg body.'
Answer:
1306.66N
Explanation:
Given data
r=12.0 m
v=14 m/s
m= 80kg
From the formula
F= mv^2/r
substitute
F= 80*14^2/12
F= 80*196/ 12
F= 15680/12
F=1306.66N
Hence the force applied is 1306.66N
Help please thank you
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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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.
The provided text reads: "a typical lightning bolt may transfer 10^20 electrons in a fraction of a second, developing a peak current of up to 10 kiloamperes." Using the value of the elementary charge of 1.6x10^-19 C We can estimate the total charge of the lightning bolt to be about *
1.6E1 C
1.6E4 C
1.6E10 C
1.6E20 C
Answer:
1.6e20
Explanation:
10. A 50 kg bicyclist on a 10 kg bicycle speeds up from 5.0 m/s to 10 m/s.
(a) What was the total kinetic energy before accelerating? Full working out
Answer:
T.K.E = 750 Joules.
Explanation:
Given the following data;
Initial velocity, u = 5m/s
Final velocity, v = 10m/s
Mass of bicyclist = 50kg
Mass of bicycle = 10kg
Total mass, Tm = 50 + 10 = 60kg
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}mv^{2}[/tex]
Where;
K.E represents kinetic energy measured in Joules.
m represents mass measured in kilograms.
v represents velocity measured in metres per seconds square.
To find the total kinetic energy before accelerating simply means the kinetic energy due to the initial velocity and total mass;
[tex] T.K.E = \frac{1}{2}T_{m}U^{2}[/tex]
Substituting into the equation, we have;
[tex] T.K.E = \frac{1}{2}*60*5^{2}[/tex]
[tex] T.K.E = 30*25 [/tex]
T.K.E = 750 Joules.
Arrange the following substances from the lightest to the heaviest:
Cl2, CH4; H20; NH3, N2
A. H2O<NH,< N2 CH4Cl2
B. CH< NH< H-0< < Cl2
C. Ny< Cl< H2O< CH«<NH3
D. NH;< CH«< Cl< H2O< N2
molecular weights are written in the picture.
CH4<NH3<H2O<Cl2
Choose five chemical changes from the list below.
running in place
dropping a glass
rotting milk
apples getting ripe
smashing a rock
digesting your lunch
burning paper
cutting up an apple
iron rusting
3. A backpack weighs 8.2 N and has a mass of 5 kg on the moon. What is t
strength of gravity on the moon?
8.2 N
An aspirin tablet that contains 75mg of
aspirin and 325mg of inert materials is an
example of
A. qualitative data.
B. quantitative data.
C. neither qualitative or quantitative data.
Answer:
it is for sure B. Quantitative data !
Explanation:
As I learned from quizlet!. there your welcome
Answer:
B. Quantity
Explanation:
This is easy
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!
what is agrculture and it means
Agriculture is the science, the practice of cultivating the soil, art, producing crops, raising livestock, and in varying degrees the preparation and marketing of the resulting products cleared the land to use for agriculture.
Explanation:This is what I found during my research and I hope this helps. Correct me if I am incorrect! Have a good one.
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