Answer:
Explanation:
Let the highest and lowest score be a and b respectively .
a - b = 10
a = 10 + b
The numbers in descending order are a , 98 , 98 , b .
mean = 100 , so
4 x 100 = a + 98 + 98 + b = 10 + b + 98 + 98 + b = 206 + 2b
400 = 206 + 2b
2b = 194
b = 97
a = 107
So the scores were as follows
107 , 98 , 98 , 97
How much power does an Ox pulling a plow 20 m cross a field, exerting 120J of work over a period of 15 s?
Answer:
8W
Explanation:
Given parameters:
Distance covered = 20m
Work done = 120J
Time = 15s
Unknown:
How much power does the Ox exerts = ?
Solution:
Power is the rate at which work is being done
Power = [tex]\frac{Work done }{time}[/tex]
Power exerted by ox = [tex]\frac{120}{15}[/tex] = 8W
What is Required for the energy of an object to change
Tafu is working with subatomic particles in the physics lab. a positron is traveling in a straight line down the particle accelerator. tafu models its position with the function p(t)= t2 t â 1 where t>1. in the limit calculations below, if you need to use -â or â, enter -infinity or infinity. (a) calculate the limit
Answer:
Infinity
Explanation:
When you have a limit approaching infinity one method you can use is to remember that the highest power dominants all of the other ones so when we have (t^2)/t-1 like in your problem, we see that t^2 has the highest power of 2 so if that's going to infinity and it's not being divided by any powers higher than it will just be inifinity.
We have that for the Question, it can be said that in the limit calculations below, if you need to use -â or â, enter -infinity or infinity. the limit is
[tex]Lim_{t->\infty} p(t)= \infty[/tex]
From the question we are told
Tafu is working with subatomic particles in the physics lab. a positron is traveling in a straight line down the particle accelerator.tafu models its position with the function
p(t)= t2 t â 1 where t>1.
in the limit calculations below, if you need to use -â or â, enter -infinity or infinity.
(a) calculate the limit
Generally the equation for the Question is mathematically given as
[tex]p(t)=\frac{t^2}{t-1}\\\\Therefore\\\\For Lim_{\infty}\\\\We have\\\\ Lim_{t->\infty} p(t)= Lim_{t->\infty}\frac{t^2}{t-1}\\\\[/tex]
Since, the equivalent degree of numerator (t^2) is greater than that of the denominator
[tex]Lim_{t->\infty} p(t)= \infty[/tex]
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1. A heat engine has a cold reservoir that is 285 degrees Kelvin which accepts 370 J of heat, and a hot reservoir that is 371 degrees Kelvin which gives off 425 J of heat. Calculate the maximum and actual efficiencies of this engine.
2. A system that has a total change in entropy of 675 J/K and has received 243 J of heat energy will be at what temperature?
3. Assume that the above system maintains a constant pressure, and increases in volume by 2.5 m 3 while doing this work. What is the pressure of the system?
I can't help with this one.
The maximum efficiency of the heat engine is 23%.
The actual efficiency of the heat engine is 13%.
The temperature of the system is 273.36 ⁰C.
The pressure of the system is 607.5 Pa.
The given parameters:
Cold reservoir temperature, Tc = 285 KHeat, qc = 370 JHot reservoir temperature, Th = 371 KHeat of the hot reservoir, qh = 425 JThe maximum efficiency of the heat engine is calculated as follows;
[tex]\eta = 1- \frac{T_c}{T_h} \\\\ \eta = 1 - \frac{285}{371} \\\\ \eta = 0.23\\\\ \eta = 23 \ \%[/tex]
The actual efficiency of the heat engine is calculated as follows;
[tex]\eta = 1 - \frac{q_c}{q_h} \\\\ \eta = 1 - \frac{370}{425} \\\\ \eta = 0.13\\\\ \eta = 13\ \%[/tex]
The temperature of the system is calculated as follows;
[tex]\Delta S = \frac{\Delta H}{T} \\\\ T = \frac{\Delta H}{\Delta S}\\\\ T = \frac{243}{675} \\\\ T = 0.36 \ K\\\\ T = 273.36 \ ^0C[/tex]
The pressure of the system is calculated as follows;
[tex]W = P \Delta V\\\\ P = \frac{W}{\Delta V} \\\\ P = \frac{243}{2.5} \\\\ P = 607.5 \ Pa[/tex]
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what are the rocky planets? theres more in the attachment
HELP ME PLS
Answer:
Explanation:
The rocky planets include Mercury, Venus, Earth, and Mars. they are made up of rocks and metals and have solid surfaces.They are the closest four planets to the Sun. The gas giants are Neptune, Uranus, Saturn, and Jupiter. they are further from the sun and are in the outer part of the solar system. I hope this helps!
How much thermal energy does it take to raise the temperature of 2.5 kg of
plastic from 15°C to 75°C? The specific heat of plastic is 2.60 kJ/(kg.°C)
Answer:
390kJ
Explanation:
A force of 6.0 Newton’s is applied to a block at rest on a horizontal frictionless surface over a 7.0 meter span. How much energy is gained by the block.
Answer:
42J
Explanation:
Given parameters:
Force applied = 6N
Distance moved = 7m
Unknown:
Amount of energy gained by the block = ?
Solution:
The amount of energy gained by the block is the same as the work done on the block.
The work done is the force applied to move the block through a distance;
Energy gained = force x distance = 6 x 7 = 42J
A 1.4 kg coconut falls from rest out of a tree. The instant before it hits the ground, it has a velocity of 6.7 m/s. How high was the coconut initially?
Answer:
2.29m
Explanation:
Given parameters:
Mass of the coconut = 1.4kg
Final velocity = 6.7m/s
Initial velocity = 0m/s
Unknown:
Height of the coconut initially = ?
Solution:
To solve this problem, we use one of the kinematics equation. The one given below is the best one to use.
V² = U² + 2gH
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
H is the height
So;
6.7² = 0² + (2 x 9.8 x h)
44.89 = 19.6h
h = 2.29m
Can a solution be separated by filtration?
Answer:
Filtration is a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered: the sand stays behind in the filter paper (it becomes the residue ) the water passes through the filter paper (it becomes the filtrate )
Explanation:
Listo!
What happens when stress builds up at faults?
A. Energy is absorbed
B. Rock can bend and break
C. Plates form on the lithosphere
D. earthquakes develop at earths surface
Answer:
The answer is D because when the faults move that is the tectonic plates moving. So earth quakes will be forming when the fault moves.
Explanation:
A spring has a constant of 875 N/m. What hanging mass will cause this spring to stretch 4.5 m?
Answer:
8) A hanging 7.5 kg object stretches a spring 1.1 m. What is the spring constant? 1 . 1 66. 82 NIMO 9) A spring has a constant of 875 N/m. What hanging mass will cause this spring to stretch 4.5 m? Iouliply then divide 875 X 4. 2- - (4 04. 7919) 10) A spring with a spring constant of 25 N/m is stretched 65 cm. What was the force used? 11) A 25 N force stretches a spring 280 cm. What was the spring constant? 12) A 75 N force stretches a spring 175 cm. What was the proportionality constant? 8) 66.82 N/m 9) 401.79 kg 10) 16.25 N 11) 8.93 N/m 12) 42.86 N/m
Explanation:
A spring has a constant of 875 N/m. and the mass which will cause this spring to stretch 4.5 meters is 401.78 kg.
What is Spring constant?The spring constant is a characteristic of a spring which is defined as the ratio of the force affecting the spring to the displacement which is caused by that force. The SI unit of spring constant is N.m⁻¹ (Newton per meter).
The spring constant is:
F = -k/ x
where, k is the spring constant
F denotes the force,
and x denotes the change in the length of the spring.
k = 875N/m
x = 4.5m
We know that
Kx = mg
m= kx/ g
m = 875 × 4.5/ 9.8
m = 401.78kg
Therefore, the mass which will cause this spring to stretch 4.5 meters is 401.78 kg.
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Scientists have made predictions about the universe today based on the big bang theory. Observations that match these predictions support the big bang theory. Which of the following observations have scientists made that provides evidence of the big bang?
A. Light from the moment of the big bang has been observed.
B. The percentages of hydrogen and helium match the predicted percentages.
C. Galaxies are moving toward each other as predicted by the big bang theory.
D. Many galaxies that are similar to the Milky Way have been observed.
Answer:
the answer is b
Explanation:
Answer:
b
Explanation:
I just did it on a p e x
f. It is easier to pull a lawn roller than to push it, why?
Answer:
because you use more force to push than to pull (well it depends how heavy it is)
Explanation:
Do all metals stick to magnets? Give an example. I NEED HELP FASTT
Answer:
No
Explanation:
Not all metals stick to magnets. Like aluminum. if you were to stick a magnet on to an aluminum it would fall off.
Which of the following statements is true?
A.
Most metals and nonmetals conduct electricity well, but metals cannot conduct heat.
B.
Most nonmetals can be drawn into a wire, while metals would break apart.
C.
Most metals and nonmetals conduct heat well, but nonmetals cannot conduct electricity.
D.
Most metals can be drawn into a wire, while nonmetals would break apart.
Answer:
D. Most metals can be drawn into a wire, while nonmetals would break apart
Explanation:
The correct statement from the given choices is that most metals can be drawn into a wire while non-metals would break apart.
Metals are malleable due to the presence of metallic bonds between their atoms. The large electron cloud due to the electropositivity of metals allows for the wide range of physical properties observed in them.
Metals are also conductors because they have free mobile electrons. Therefore they can conduct heat and electricity.Non-metals are brittle and cannot conduct neither heat nor electricity.
Why is NEWTON'S First Law of Motion often called the LAW OF INERTIA?
Answer:
According to newtons first law of motion an object remains in its state of rest or motion in a straight line unless an external unbalanced forces acts upon it. This is the reason why Newtons first law of motion is often called the LAW OF INERTIA
An elephant kicks a 2.5 kg rock that is initially at rest. The
net force on the rock varies with time as shown below.
What is the rock's change in momentum between 0 ms
and 20 ms?
0.20Answer:
Explanation:
Juan rides his horse with a constant
speed of 18 km/h. How far can he travel
in 1/2 hour?
Answer:
He traveled 9km
Explanation:
To do this problem you need to use the equation which is Speed= distance/time and this problem gives you the speed which is 18 km/h and it gives you the time 1/2 hour so you write the equation 18= d/ 1/2 which his distance is 9km
Martha, a first-grade teacher, is worried that if doesn't stay In at work to grade papers her principal will think she is lazy She is also worried that if she stays late at work her partner will be angry. This of conflict is known as
Answer:
Character vs self
Explanation:
The reason is because Martha is thinking to much about the negative things and it is making her feel like she is fighting her own body for control.
how much energy must be absorbed by water with a mass of 0.5kg in order to raise the tempature from 30c to 65c
Answer:
62760J
Explanation:
Given parameters:
Mass = 0.5kg = 500g
Initial temperature = 30°C
Final temperature = 65°C
Unknown:
How much energy is absorbed by the water = ?
Solution:
To solve this problem, we use the expression below:
H = m C Δt
H = m x C x (t₂ - t₁ )
m is the mass
C is the specific heat = 4.184J/g°C
t₂ is the final temperature
t₁ is the initial temperature
So;
H = 500 x 4.184 x (65 - 30) = 62760J
There are several ways to model a compound. One type of model is shown.
What is the chemical formula for the molecule represented by the model?
CHO
C4H9O2
C4H8O
C3H8O2
Answer:
What is the chemical formula for the molecule represented by the model?
[tex] →CHO\\ →C_4H_9O_2✓ \\→C_4H_8O \\ →C_3H_8O_2[/tex]
2) C4H9O2 is the right answer.Plants are eaten by grasshoppers, which are eaten by mice, which are eaten by snakes.
Answer:
food chain / web lol? was this a question?
The tensions in the rope are 12 n and 10 n . What is the angular acceleration of the pulley?
Answer:
[tex]\mathbf{\alpha = 16.06 \ rad/s^2}[/tex]
Explanation:[tex]A \ frictionless \ pulley, \ whic h\ can \ be \ modeled \ as \ a \ 0.83 k g \ solid \ cylinder \ with \ a \ 0.30 \ m \ radius,[/tex] [tex]\ has \ a \ rope \ going \ over \ it[/tex] [tex]The \ tensions \ in \ the \ rope \ are \[/tex] [tex]12 n \ and \ 10 n . \ What \ is \ the \ angular \ acceleration \ of \ the \ pulley?[/tex]
[tex]From \ the \ given \ information:[/tex]
[tex]The \ moment \ of \ inerti a \ of \ a \ solid \ cylinder[/tex] [tex]I = \dfrac{1}{2}mr^2[/tex]
[tex]I = \dfrac{1}{2}(0.83)(0.3)^2[/tex]
[tex]I = 0.03735 \ kg \ m^2[/tex]
[tex]The \ net \ torque = F_1(r) - F_2(r) \\ \\ = 12(0.3) - 10(0.3) \\ \\ = 0.6 \ N.m[/tex]
[tex]Torque (T) = moment \ of \inertia (I) \times angular \ acceleration ( \alpha)[/tex]
[tex]\alpha = \dfrac{T}{I}[/tex]
[tex]\alpha = \dfrac{0.6 \ Nm}{0.03735 \ kg \ m^2}[/tex]
[tex]\mathbf{\alpha = 16.06 \ rad/s^2}[/tex]
A stationary 10 kg object is located on a table near the surface of the earth. The coefficient of kinetic friction between the surfaces is 0.2. A horizontal force of 40 N is applied to the object.
Answer:
2.04m/s²
Explanation:
Complete Question
A stationary 10 kg object is located on a table near the surface of the earth. The coefficient of kinetic friction between the surfaces is 0.2. A horizontal force of 40 N is applied to the object. Find the acceleration of the object.
According to Newtons second law;
\sum F_x = ma_x
F_m - F_f = ma_x
Fm is the applied force
Ff is the frictional force
m is the mass
a is the acceleration
Substitute the given values
40N - nmg = 10a
40 - 0.2(10)(9.8) = 10a
40 - 19.6 = 10a
20.4 = 10a
a = 20.4/10
a = 2.04m/s²
Hence the acceleration of the object is 2.04m/s²
Which part of the electromagnetic spectrum is typically used to make images based on the temperatures of objects?
X-rays
radio waves
infrared light
visible light
Answer:
Which part of the electromagnetic spectrum is typically used to make images based on the temperatures of objects?
X-rays
radio waves
infrared light<<<----- CORRECT
visible light
Explanation:
Edge 2021
Infrared light is typically used to make images based on the temperatures of objects.
What is meant by electromagnetic spectrum?The range of all EM radiation arranged from high to low frequency (short to long wavelength) according to their frequency or wavelength. is known as the electromagnetic spectrum (EM).
Here,
Similar to visible light, X-rays are a type of electromagnetic radiation. X-rays have a higher energy than light, on the other hand, and can penetrate most materials, including the human body.
Images of inside body tissues and structures are produced using medical x-rays.
Electromagnetic energy in the infrared region of the spectrum can be seen by them. There is a relationship between an object's temperature and the electromagnetic radiation it releases since infrared radiation is strongly related to object temperature.
Hence,
Infrared light is typically used to make images based on the temperatures of objects.
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HELP PLS MARKING BRANLIST 100 Pts TAKING TEST RN
A sprinter runs the 50 m dash in 5.6 seconds. What is the sprinter's speed?
280 m/s
0.11 m/s
44.4 m/s
8.93 m/s
Make a prediction that answers the question in the purpose:
“How does time affect the temperature of water?”
(Ex-“If we use a ramp, then the ball will roll faster down the ramp because gravity has more time to do work on the ball.”)
Im not good at these, please help quickly.
Most electricity comes from the burning of
A. Fossil fuels B. Trash C. Wood D. None of the above
Answer:
(A) Fossil Fuels
Answer:
Fossil Fuels
Explanation:
That’s what CK12 told me
I’ll give brainliest and 10 points
Answer:
what's these its D okkkk
TRUE if the statement is correct and write FALSE if is not.
1. Adolescents can achieve their energy and nutrient requirements by eating a variety of foods daily.
2. Eating regular meals will keep the body fueled by energy needed for the day.
3. Too much sweets and dessert can aggravate skin problems like pimples.
4. The Food Pyramid will guide you on how many servings from each food group is recommended daily.
5. Due to your rapid growth and development at this stage, you have a lesser need for certain nutrients, such as
calcium, iron, protein, and energy foods.
Answer:
1. True
2. True
3. True
4. True
5. False
Explanation:
1. Indeed, many health experts often recommend that when children reach the age of adolescents (between ages 10 and 19) they should eat a variety of foods daily in other to have enough energy and nutrients needed for development.
2. Having regular meals (mornings, afternoon, and evenings) has for long been encouraged by medical professionals in other to provide the body its fuel.
3. Some skin problems have long been associated with too much consumption of sweets and desserts since these products often contain sugars, and excess processed sugar intake is said to increase acne and eczema.
4. Just as the name suggests, the food pyramid is a visual representation that contains how many servings from each food group in other be healthy.
5. This is false because throughout the growth stages of life it is essential to get the needed food nutrients such as calcium, iron, protein, and energy foods.
