Answer:
1 m²Explanation:
The area of the floor covered by his both feet can be found by using the formula
[tex]a = \frac{f}{p} \\ [/tex]
f is the force
p is the pressure
From the question we have
[tex]a = \frac{400}{400} = 1 \\ [/tex]
We have the final answer as
1 m²Hope this helps you
Electric power is to be generated by installing a hydraulic turbine-generator at a site 70 m below the free surface of a large water reservoir that can supply water at a rate of 1500 kg/s steadily. If the mechanical power output of the turbine is 800 kW and the electric power generation is 750 kW, determine the turbine efficiency and the combined turbine–generator efficiency of this plant. Neglect losses in the pipes.
Answer:
[tex]\eta_{turbine} = 0.777 = 77.7\%[/tex]
[tex]\eta_{combined} = 0.728 = 72.8\%[/tex]
Explanation:
First we calculate the power input to the turbine. The input power will be equal to the potential energy of water per unit time:
Input Power = [tex]P_{in} = \frac{Work}{Time} = \frac{Potential\ Energy\ of\ Water}{t} \\P_{in} = \frac{(mass)(g)(height)}{Time} = (mass flow rate)(g)(height)\\\\P_{in} = (1500\ kg/s)(9.81\ m/s^2)(70\ m)\\P_{in} = 1.03\ x\ 10^6\ W = 1030\ KW[/tex]
Now, for turbine efficiency:
[tex]\eta_{turbine} = \frac{Mechanical\ Power\ Out}{P_{in}}\\\\\eta_{turbine} = \frac{800\ KW}{1030\ KW}\\\\\eta_{turbine} = 0.777 = 77.7\%[/tex]
for generator efficiency:
[tex]\eta_{generator} = \frac{Power\ Generation}{Mechanical\ Power\ Out}\\\\ \eta_{generator} = \frac{750\ KW}{800\ KW}\\\\\eta_{turbine} = 0.9375 = 93.75\%[/tex]
Now, for combined efficiency:
[tex]\eta_{combined} = \eta_{turbine}\ \eta_{generator}\\\\\eta_{combined} = (0.777)(0.937)\\\eta_{combined} = 0.728 = 72.8\%[/tex]
The force of air particles over an area is ________
temperature.
pressure.
volume.
kelvins.
type of energy found in bread
Answer:
Bread contains energy in form of
Carbohydrates
Explanation:
Answer:
CHEMICAL ENERGY
Should the resistance of an ammeter low or high ?give reason
Answer:
The resistance of an ammeter should be low. This is because an ammeter is connected in series with the circuit for the measurement of electric current. In case, its resistance is high, then some amount of current may lost in heating it leading to the inaccurate reading. An ideal ammeter is one which has zero resistance.
where does reduction occur in an electrolytic cell
a. cathode
b. salt bridge
c. anode
d. wire
Answer:
The answer is actually a. Cathode
Explanation:
Just took the quiz
In an electrolytic cell, the reduction occurs at the cathode. So, the correct option is a.
What is meant by reduction ?Reduction is defined as the process through which a reactant gain electrons during a chemical reaction.
Here,
An electrolytic cell is an equipment that uses electric current to drive a redox reaction.
Redox reactions are the type of reaction that involves the transfer of electrons between the reactants. That means, in redox reactions, both oxidation and reduction occurs. The reactant that gains the electrons is said to be reduced and the one that losses the electrons is said to be oxidized.
In an electrolytic cell, cathode is the positively charged electrode. So, electrons are attracted towards it, and as a result, the cathode gets reduced.
Hence,
In an electrolytic cell, the reduction occurs at the cathode.
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A person pours some chlorine bleach into a clothes washer to remove stains from the clothing. What is one chemical property or the bleach?
A. It’s density
B. It’s mass
C. It’s color
D. It’s pH
One chemical property of the bleach is its pH.
What is pH?This is referred to as the power of hydrogen and is a measure of how acidic/basic a substance is.
pH is an example of chemical property because it's associated with a change in its chemical composition. This thereby makes option D the most appropriate choice.
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Answer: It's pH
Explanation: I took the test
A baseball on the Moon and an identical baseball on the Earth are thrown vertically upward with the same initial velocity of 12 m/s. The acceleration due to gravity on the Moon is 1/6 that of Earth. What is the maximum height the ball reaches on the moon? What is the maximum height the ball reaches on the earth? What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?
Answer:
a. 3.68 m b. 0.61 m c. 3.07 m
Explanation:
a. What is the maximum height the ball reaches on the moon?
Using v² = u² - 2g'h where u = initial velocity of baseball = 12 m/s, v = final velocity of baseball = 0 m/s (since it stops at maximum height), g' = acceleration due to gravity on moon = g/6 where g = acceleration due to gravity on earth = 9.8 m/s², so g' = 9.8 m/s²/6 = 1.63 m/s² and h = maximum height of ball on moon.
So, making h subject of the formula, we have
h = -(v² - u²)/2g'
substituting the values of the variables, we have
h = -((0 m/s)² - (12 m/s)²)/2(1.63 m/s²)
= -(- 12 m²/s²)/2(1.63 m/s²)
= 6 m²/s²)/(1.63 m/s²)
= 3.68 m
b. What is the maximum height the ball reaches on the earth?
Using the same equation for the maximum height the baseball travels on the moon for that on the earth, the maximum height h' the baseball travels on the earth is given by
h' = -(v² - u²)/2g where u = initial velocity of baseball = 12 m/s, v = final velocity of baseball = 0 m/s (since it stops at maximum height), g = acceleration due to gravity on earth = 9.8 m/s²and h' = maximum height of ball on moon.
substituting the values of the variables, we have
h = -((0 m/s)² - (12 m/s)²)/2(9.8 m/s²)
= -(- 12 m²/s²)/2(9.8 m/s²)
= 6 m²/s²)/(9.8 m/s²)
= 0.61 m
c. What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?
The difference in the maximum height the ball reaches on the Moon compared to on Earth is d = h - h' = 3.68 m - 0.61 m = 3.07 m
pins accompained by a ball bowling dates back to what era
How do I calculate how many meters are in 7.2 light years?
The exact question is:
Calculate in meters the distance between a galaxy and the Earth if the distance is equal to 7.2 light years.
Answer:
68.2 Quadrillion meters
Explanation:
A lightyear is the distance that light travels in one year.
Speed of light is [tex]3*10^8\ m/s[/tex]
So light covers 300,000,000 meters in one second.
One year has 31536000 seconds so , light covers
[tex]9.461*10^{15}\ meters\ in\ one\ year[/tex]
so 7.2 light years is
[tex]7.2*(9.461*10^{15})\\6.82*10^{16}[/tex]
so 7.2 light years is
6.82 x 10^(16) meters or
68.2 Quadrillion meters
A stone takes 5.4 seconds to fall from the top of a cliff. The cliff is
meters high.
143
53
286
573
Answer:
143
Explanation:
Using one of the 3 fundamental equations in physics, y=vo*t+1/2gt^2, we can use this equation to find the total distance that was traveled.
Acceleration due to gravity is always 9.8m/s^2 and time is 5.4s, we also have no initial velocity.
Given this, we can plug in the known variables.
y=0t+1/2*9.8*5^2
simplify,
y=4.9*5.4^2
y=4.9*29.16
y=142.884m which we can round up to 143 meters
Final Answer: 143 meters
Help please!!!
if superman at 90kg jumps a 40m building in a single bound how much work does superman perform
Answer:
5 years worth of work (aka all of the homework i currently have)
water starts to freeze from top whereas wax starts to freeze from bottom?why?
Answer:
im pretty sure its because wax has i higher melting point therefore it would cool quicker if the temperature dropped more. water has a lower melting point so it takes longer to freeze i think. i hope this helps
Water and wax freeze from different directions due to the unique properties and behaviors of these substances.
Water:
When water freezes, it undergoes a phase transition from a liquid to a solid state.
Unlike most substances, water exhibits an unusual property known as the "anomalous expansion of water" or "density anomaly." This anomaly is caused by the hydrogen bonding between water molecules.
As the water cools down, its molecules begin to slow down and move closer together. This causes the density of the water to increase. However, as the water reaches around 4 degrees Celsius (39 degrees Fahrenheit), it starts to behave differently.
The hydrogen bonds between water molecules become more organized and stable, causing the water to expand and become less dense.
Wax:
Wax, on the other hand, does not exhibit the same density anomaly as water. When wax undergoes solidification, it follows a different pattern due to its molecular structure and the way its particles arrange themselves.
Wax typically consists of long, nonpolar hydrocarbon chains. As it cools, the wax molecules start to lose kinetic energy, slowing down their movement.
The intermolecular forces between the wax molecules become stronger, causing them to come closer together.
In summary, water freezes from the top due to its density anomaly, with the less dense, expanded water rising and forming a layer of ice on the surface.
Wax, however, freezes from the bottom as its molecules arrange and bond together, gradually solidifying upwards. These differences in freezing behavior are influenced by the distinct properties and molecular structures of water and wax.
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Ronald observes a large island off the coast of Indonesia on a map. A few months later, he observes that there are many smaller islands in place of the large one he had seen earlier. Which of these could have caused this change?
Answer:
idgaf
Explanation:
lol
Which of the following is the keyboard shortcut for saving a document?
O Control V
O Control S
O Control A
O Control E
Answer:Control S, Command S on MAC=Save
what power is transmitted by 2A flowing across 5V
Answer:
[tex]\huge\boxed{10\:watts}[/tex]
Explanation:
Power = Current × Voltage
P = I × V
P = 2 × 5
P = 10 watts
An object is thrown straight up into the air with an initial speed of 8 m/s, and reaches a greatest height of 15 m before it falls back to the ground. a. What height is the object thrown from? b. How long does it take for the object to hit the ground?
Answer:
The value is [tex]T_t = 2.5659 \ s[/tex]
Explanation:
From the we are told that
The initial speed of the object is [tex]u = 8 \ m/s[/tex]
The greatest height it reached is [tex]h = 15 \ m[/tex]
Generally from kinematic equation we have that
[tex]v^2 = u^2 + 2gH[/tex]
At maximum height v = 0 m/s
So
[tex]0^2 = 8^2 + 2 * - 9.8 * H[/tex]
=> [tex]H = 3.27 \ m[/tex]
Here H is the height from the initial height to the maximum height
So the initial height is mathematically represented as
[tex]s = h - H[/tex]
=> [tex]s = 15 - 3.27[/tex]
=> [tex]s = 11.73 \ m[/tex]
Generally the time taken for the object to reach maximum height is mathematically evaluated using kinematic equation as follows
[tex]v = u + (-g) t[/tex]
At maximum height v = 0 m/s
[tex]0 = 8 - 9.8t[/tex]
=> [tex]t = 0.8163 \ s[/tex]
Generally the time taken for the object to move from the maximum height to the ground is mathematically using kinematic equation as follows
[tex]h = ut_1 + \frac{1}{2} gt_1^2[/tex]
Here the initial velocity is 0 m/s given that its the velocity at maximum height
Also g is positive because we are moving in the direction of gravity
So
[tex]15 = 0* t + 4.9 t^2[/tex]
=> [tex]t_1 = 1.7496[/tex]
Generally the total time taken is mathematically represented as
[tex]T_t = t + t_1[/tex]
=> [tex]T_t = 0.8163 + 1.7496[/tex]
=> [tex]T_t = 2.5659 \ s[/tex]
An object weighing 49 N is pushed across a floor by a force of 12 N. What is the acceleration of the object?
Answer:
Explanation:
Given parameters:
Weight of object = 49N
Force applied = 12N
Unknown:
Acceleration of object = ?
Solution:
The acceleration of the object is found by dividing the force by the weight;
Acceleration = [tex]\frac{12}{49}[/tex] = 0.25m/s²
Which element accumulates in the environment due to the use of
fertilizers?
A. oxygen
B. hydrogen
C. nitrogen
D. carbon
To Find :
Which element accumulates in the environment due to the use of fertilizers.
Solution :
Most of the fertilizers used in daily practice are nitrogen fertilizers .
When soil became waterlogged, soil organisms take the oxygen they need from nitrates, leaving the nitrogen in a gaseous form which escapes into the air.
Also, nitrogen is very stable and did not participate in most of the reactions.
So, nitrogen is accumulates in the environment .
Therefore, option C. is correct.
A 20 kg mass is hanging on one side of a pulley and a 5 kg mass is hanging on the other. Determine the acceleration of each mass.
Answer:
i believe it's 7
Explanation:
Form hypothesis: How do you think increasing the resistance in a circuit will affect the current in the wire? (format: if, then, because)
Answer:it would make it thicker
Explanation:
Answer:
"The equation shows that the current in a circuit is inversely proportional to the resistance of the circuit. An increase in resistance would result in a decrease in current. And the factor by which the resistance increases is the same factor by which the current decreases."
Explanation:
Because it's just like wearing a glove/mitten when getting something out of the oven, because of the insulation from the glove/mitten, it reduces the heat that gets through into your hand, and it protects it. Just like what the "answer" says, it said that the resistance would decrease current.
Help me pretty please with a cherry on top!!
Answer:
A. im not for sure hope it helps
Explanation:
21. A teacher does the following:
i. walks 4 m, south
ii. walks 8 m, east
iii. walks 4 m, north
iv. walks 8 m, west.
The overall displacement of the teacher is
a. Om
b. 6 m
c. 12 m
d. ... Nonsense! It cannot be calculated without knowing time information.
Answer:
displacement is the change from a starting point. she ends up back where she started so her displacement is zero meters although she traveled 24m in all.
If the person's velocity is changing is the person
accelerating
Answer:
a change in velocity can be a change in magnitude (or speed), but it can also be a change in direction.
Identify the type of motion that occurs when a body moves around its own center of mass.
circular
revolution
rotation
resolution
Answer:
circular
Explanation:
If you have 100 kg of each of these substances, which would require the most energy to increase its temperature by 25 Kelvin?
A. iron
B. carbon
C. rubber
D. air
Answer:
a
Explanation:
Answer:
A Iron
Explanation:
Hope this helps :D
A rat runs 2m right, turns around and runs 3m left. Then goes 2m right. What is its displacement?
A. 1m right
B. 1m left
C. 7m
D. 7m left
Answer:
Explanation:
I think this answer would be 1m to the left.
Which of these games was a racing game?
A.
Centipede
B.
Pole Position
C.
Xevious
D.
Galaxian
E.
Space Invaders
Answer:
B.
pole position
A duck is floating in a pond. How does Archimedes' description of the buoyant force explain why the duck
doesn't sink?
PLEASE HURRY
Answer:
The upthrust or buoyant force helps the duck doesn't sink.
For example, there is a duck which weighs 3 pounds and tree pints of water also weigh three pounds. In this case the volume of the duck is more than the volume of three pints of water, so the duck floats.
Hope it helps!<3
Hardin electronic corporation is designing a new cell phone, they need a solid material that will insulate the phone and product their users from electric shock. Which material would best fit the needs of Hardin engineers A. A non-metal B. A metalloid C. A metal D. A semiconductor
Answer:
A
Explanation:
The material that would best suit Hardin electronic corporation's need would be a non-metal.
Non-metals are naturally occurring substances or materials that lack the properties of metals. In other words, non-metals are poor conductors of heat and electricity, unlike metals.
Solid non-metals are, therefore, used as insulators in the design of materials. Hence, the best material for Hardin electronic corporation to use that will insulate the phone and protect their users from electric shock would be a non-metal.
The correct option is A.
how longitudinal waves are formed
Answer:
forever
Explanation:
