PLSS HELPP
Are humans evolving? What will humans look like in 100,000 years in the future or longer?
Answer:
yes
Explanation:
1.45 L of 16°C water is placed in a refrigerator. The refrigerator's motor must supply an extra 10.7 W power to chill the water to 6°C in 0.7 hr. What is the refrigerator's coefficient of performance?
Answer:
The coefficient of performance of the refrigerator is 2.251.
Explanation:
In this case, the coefficient of performance of the refrigerator ([tex]COP[/tex]), no unit, is equal to the ratio of the heat rate received from the water to the power needed to work, that is:
[tex]COP = \frac{\dot Q_{L}}{\dot W}[/tex] (1)
[tex]COP = \frac{\rho\cdot V\cdot c_{w}\cdot \Delta T}{\dot W \cdot \Delta t}[/tex] (2)
Where:
[tex]\dot Q_{L}[/tex] - Heat rate received from the water, in watts.
[tex]\dot W[/tex] - Power, in watts.
[tex]\rho[/tex] - Density of water, in kilograms per cubic meter.
[tex]V[/tex] - Volume of water, in cubic meters.
[tex]c_{w}[/tex] - Specific heat of water, in joules per kilogram-degree Celsius.
[tex]\Delta T[/tex] - Temperature change, in degrees Celsius.
[tex]\Delta t[/tex] - Cooling time, in seconds.
If we know that [tex]\rho = 1000\,\frac{kg}{m^{3}}[/tex], [tex]V = 1.45\times 10^{-3}\,m^{3}[/tex], [tex]c_{w} = 4187\,\frac{J}{kg\cdot ^{ \circ}C}[/tex], [tex]\Delta T = 10\,^{\circ}C[/tex], [tex]\dot W = 10.7\,W[/tex] and [tex]\Delta t = 2520\,s[/tex], then the coefficient of refrigeration of the refrigerator is:
[tex]COP = \frac{\rho\cdot V\cdot c_{w}\cdot \Delta T}{\dot W \cdot \Delta t}[/tex]
[tex]COP = 2.251[/tex]
The coefficient of performance of the refrigerator is 2.251.
Why is the magnetic force considered to be an action datance force
A Magnets in de bo exert a force
B. Magnets do not have to touch each other to experience a force.
C. Magnets push each other apan to increase the distance between them.
D Magnets mast be large in sire in onder to eden a force that is strong enough to notice
Only the healthy foods we eat provide
energy to our body
true
false
Answer:
True
Explanation:
Yes absolutely the food which provede us energy is termed as healthy..
how long would it take a leopard, running at an average speed of 20 m/s to travel 500 m?
Answer:
25 seconds
Explanation:
500/20
HELP pleaseee which nucleus completes the following equation?
Answer:
its D
Explanation:
i just got it correct on a. p. e. x. :)
Blackie, a cat whose mass is 6-kg, is napping on top of the refrigerator when he rolls over and fall. Blackie has a KE of 90-J just before he lands on his feet on the floor.
How tall is the refrigerator?
To answer this question, you need to understand the law of conservation of energy. Essentially, the law states that energy cannot be created or destroyed; it is always conserved.
Knowing this law, how can we answer this question? Well, let's look at what the question tells us. We know that Blackie was initially at the top of a refrigerator before rolling over and falling to the ground. At ground level, he only has Kinetic energy when he lands. Since we know that he started at the top of the fridge, we know that Blackie started off with potential gravitational energy.
That would make sense, right? Written out as an equation, it'd be:
[tex]U_{g}[/tex] = [tex]K_{E}[/tex]
This follows the law of conservation of energy, as all the potential gravitational energy is converted into Kinetic energy.
Now, we know what energies are converted. What can we do with it? Recall the equation of potential gravitational energy:
[tex]U_{g}[/tex] = [tex]F_{g}[/tex]∆H
[tex]U_{g}[/tex] = mg∆H
Do you see it now? ∆H is the distance that Blackie falls, and since Blackie jumps from the fridge to the ground, ∆H must be the height of the fridge!
Let's start solving for ∆H:
[tex]U_{g}[/tex] = [tex]K_{E}[/tex]
Substitute potential gravitational energy with our equation:
mg∆H = [tex]K_{E}[/tex]
We were given the value of Kinetic Energy:
mg∆H = 90
Isolate ∆H by dividing both sides by mg:
∆H = [tex]\frac{90}{mg}[/tex]
Input values for 'm' and 'g' (m is the mass of Blackie and g is Earth's acceleration)
∆H = [tex]\frac{90}{6*9.80}[/tex]
∆H = [tex]\frac{90}{58.8}[/tex]
∆H = 1.53
The refrigerator is 1.53 meters tall.
And that's it! Let me know if you need me to explain anything I did here.
- breezyツ
The _____________ variable is observed, measured, and affected by the independent variable.
Answer: It would be the dependent variable.
Explanation:
The dependent variable is limited and can be affected by the changes and manipulation of the independent variable.
Waves that move through space are called
Answer:
Electromagnetic waves are waves that can travel through matter or through empty space
Which person below is likely to have better health?
A. Jenna, who is optimistic about life
B. Albert, who thinks that events in his life are not in his control
C. Peter, who is depressed
D. Claire, who blames everyone else for her circumstances
SUBMIT
Jenna, who is optimistic about life, is likely to have better health. Hence, option (A) is correct.
What is mental health?Mental health affects cognition, perception, and behavior and includes emotional, psychological, and social well-being. It also affects how someone responds to stress, interacts with others, and makes decisions.
Subjective well-being, perceived self-efficacy, autonomy, competence, generational reliance, and self-actualization of one's intellectual and emotional potential are only a few examples of what is considered to be mental health.
The ability to enjoy life and strike a balance between daily activities and endeavors to develop psychological resilience may be considered a sign of mental health from the viewpoints of positive psychology or holistic approaches.
Learn more about mental health here:
https://brainly.com/question/18216607
#SPJ2
Show that liquid pressure is directly
proportional to height of liquid in a vessel.
Answer:
P=F/A where F is the weight of the water and A is the area on which it is resting. The weight of the water is mg. The mass of the water is dv where d is the density and v is the volume. Finally, the volume of the water in a vessel is equal to the area of the base of the vessel times the height of the vessel. (v=Ah)
Plugging everything in we get:
P = dAhg/A
So
P=dhg
So we have shown that liquid pressure is directly proportional to height of liquid in a vessel.
A cyclist travels 21 km in 90 minutes. Calculate, in m s–1 , the speed of the cyclist.
Answer:
35/9 m/s
Explanation:
21 km = 21000 m
90 min = 90*60 s = 5400 s
21000/5400 = 35/9 m/s
Imagine you leave the dock on a fishing boat that travels east for 30 kilometers when the captain realizes he left the fishing rods on the dock. It takes him 40 minutes to travel out against the current but only 20 minutes to return to the dock.
Answer:
Average speed is 60 km/hr whereas average velocity is 0 km/ hr.
Explanation:
The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.
A 5 kg ball is sitting on top of a hill. It has a Potential Energy of 6000J. What is the height of the ball?
Explanation:
mass=5 kg
potential energy=6000j
height=?
Now
potential energy =m.g.h
or 6000=5*9.8*h
or 6000=49h
or 6000÷49=h
or h= 122.45m
Which human activity causes the most erosion?
А
building a bridge over a river
B
cutting down trees for lumber
С
building a dam in a stream
D
planting crops in a field
Answer:
B
Explanation:
Kamal, Kamala, Krishna invert a sum of RS= 30,000 on a business in the ratio 2 : 3 : 5. Find the each of their investment.
Answer:
Explanation:
Kamal, Kamala, Krishna invert in the ratio 2 : 3 : 5.
As 2+3+5 =10, their respective share is 2/10, 3/10 and 5/10.
Sum of investment = 30000Rs
Kamal's investment = 30000 * 2/10 = 6,000 Rs
Kamala's investment = 30000 * 3/10 = 9,000 Rs
Krishna's investment = 30000 * 5/10 = 15,000 Rs
Do you think the plan for the skyscraper in California is appropriate based on its location? Why or why not? Your answer should include at least three complete sentences. (plz write out answer) (this is about earth quakes)
Answer:
No
Explanation:
No because like my other answer if we put to many diesels on it it will crack and little by little it will break eventually everyone will come tumbling into the water making them drown because they can't get the buckles loose or they wanted to save their families lives
A car and a semi-truck are both traveling along a road. Based on Newton's 2nd law, what will happen if both cars apply the same type of brakes at the same time?
Answer: ask god in your prayers
Explanation: im here for the same reason you are
I DONT KNOW THE ANSWER
Answer:
The semi-truck will stop after the car.
Explanation:
It will do that because the semi-truck has more mass than the car.
An outside thermometer reads 57°F. What is this temperature in °C? Round your answer to the nearest whole number. 14 49 71 135
Answer:
An outside thermometer reads 57°F. What is this temperature in °C? Round your answer to the nearest whole number.
14
49
71
135
answer is A:14
Explanation:
The temperature of the thermometer which reads 57 °F in degree celsius (°C) to the nearest whole number is 14 °C
Conversion formulaWe can convert from degree celsius (°C) to degree Fahrenheit (°F) with the following equation
°C = 5/9(°F – 32)
How to determine the temperature in degree celsius (°C) Temperature (°F) = 57 °FTemperature (°C) =?°C = 5/9(°F – 32)
°C = 5/9(57 – 32)
°C = 5/9 × 25
°C = 14 °C
Thus, the temperature in degree celsius (°C) of the thermometer is 14 °C
Learn more about conversion:
https://brainly.com/question/2139943
Which of the following are the two factors used to calculate average
speed? *
a. total acceleration and total time
b. velocity and time
c. total distance and total time
d. motion and time
Answer:
i think its its c but im not positive :>
Explanation:
Atmospheric pressure on the peak of Mt. Everest can be as low as 0.197 atm, which is why
climbers need to bring oxygen tanks for the last part of the climb. If the climbers carry 10.0
liter tanks with an internal gas pressure of 40 atm, what will be the volume in liters of the gas
when it is released from the tanks?
Answer:2,030
Explanation:
40 atm x 10.0 L = 400
400/0.197 atm = 2,030
Two point charges, Q1 = -1.0 PC and Q2 = +3.0 PC, are placed as shown in the diagram.
What is the vertical component of the electric field at the origin? Let the constant k = 9.0 x
109Nm²/C2
2.2 m
2.1 m Q1
O A zero
O B. -2100 N/C
O
C. 2100 N/C
o D. -8900 N/C
E. 8900 N/C
NEED ANSWER NOW
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