Answer:
b warming your hands over a campfire.
Explanation:
This is thermal radiation, not heat conduction
The tendency to pull other objects toward it is called
Answer:
""gravity. the force that pulls on objects and causes acceleration if the objects are not balanced by an opposing force. speed. distance traveled per unit time. Newton's Second Law of Motion.""
Explanation:
John, a fireman, slides down a pole when the fire alarm sounds. He reaches the ground at 5m^-1. Give that his mass is 60kg. Find the friction that acts against his motion as he slides down the pole.
based on the pattern between mass and kinetic energy illustrated in table 1 what is the missing data for the kinetic energy of a 4 kg ball at 4m/s? The answer is 32J but why is that answer correct?
I also need help on this question
Milk is a very weak acid. What might its pH value be ?
Answer:
pH value is between 6.5 and 6.8
Explanation:
Explanation:
Milk fresh from the cow typically has a pH between 6.5 and 6.7. The pH of milk changes over
A physics student of mass 43.0 kg is standing at the edge of the flat roof of a building, 12.0 m above the sidewalk. An unfriendly dog is running across the roof toward her. Next to her is a large wheel mounted on a horizontal axle at its center. The wheel, used to lift objects from the ground to the roof, has a light crank attached to it and a light rope wrapped around it; the free end of the rope hangs over the edge of the roof. The student radius 0.300 m and a moment of inertia of 9.60 kg m^2 for rotation about the axle, how long does it take her to reach the side walk, and how fast will she be moving just beofre she lands?
Answer:
The speed of the student just before she lands, v₂ is approximately 8.225 m/s
Explanation:
The given parameters are;
The mass of the physic student, m = 43.0 kg
The height at which the student is standing, h = 12.0 m
The radius of the wheel, r = 0.300 m
The moment of inertia of the wheel, I = 9.60 kg·m²
The initial potential energy of the female student, P.E.₁ = m·g·h₁
Where;
m = 43.0 kg
g = The acceleration due to gravity ≈ 9.81 m/s²
h = 12.0 h
∴ P.E.₁ = 43 kg × 9.81 m/s² × 12.0 m = 5061.96 J
The kinetic rotational energy of the wheel and kinetic energy of the student supporting herself from the rope she grabs and steps off the roof, K₁, is given as follows;
[tex]K_1 = \dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex]
The initial kinetic energy, 1/2·m·v₁² and the initial kinetic rotational energy, 1/2·m·ω₁² are 0
∴ K₁ = 0 + 0 = 0
The final potential energy of the student when lands. P.E.₂ = m·g·h₂ = 0
Where;
h₂ = 0 m
The final kinetic energy, K₂, of the wheel and student is give as follows;
[tex]K_2 = \dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]
Where;
v₂ = The speed of the student just before she lands
ω₂ = The angular velocity of the wheel just before she lands
By the conservation of energy, we have;
P.E.₁ + K₁ = P.E.₂ + K₂
∴ m·g·h₁ + [tex]\dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex] = m·g·h₂ + [tex]\dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]
Where;
ω₂ = v₂/r
∴ 5061.96 J + 0 = 0 + [tex]\dfrac{1}{2} \times 43.0 \, kg \times v_{2}^2+\dfrac{1}{2} \times 9.60 \, kg\cdot m^2 \cdot \left (\dfrac{v_2}{0.300 \, m} }\right ) ^2[/tex]
5,061.96 J = 21.5 kg × v₂² + 53.[tex]\overline 3[/tex] kg × v₂² = 21.5 kg × v₂² + 160/3 kg × v₂²
v₂² = 5,061.96 J/(21.5 kg + 160/3 kg) ≈ 67.643118 m²/s²
v₂ ≈ √(67.643118 m²/s²) ≈ 8.22454363 m/s
The speed of the student just before she lands, v₂ ≈ 8.225 m/s.
A firework is launched with a force of 700 N and a momentum of 200 kg-m/s. How much time before is explodes?
Answer:
t = 0.28 seconds
Explanation:
Given that,
Force acting on a firework, F = 700 N
The momentum of the firework, p =200 kg-m/s
We need to find the time before it explodes. Ket the time be t. We know that, the rate of change of momentum is equal to external frce. So,
[tex]F=\dfrac{P}{t}\\\\t=\dfrac{P}{F}\\\\t=\dfrac{200}{700}\\t=0.28\ s[/tex]
So, the required time is equal to 0.28 seconds.
When light passes from air into water at an angle of 60° from the normal, what is the angle of refraction? (40.6°)
Answer:
40.6°
Explanation:
The angle of refraction, when light passes from air into water at an angle of 60° from the normal, is 40.6°
What is Snell's law?It states that the ratio of sine of angle of incidence and angle of refraction is equal to the refractive index of second medium to the first medium.
sini/sinr =n₂ / n₁
Given, the light passes from air into water at an angle of 60° from the normal, the angle of incidence i = 60°, refractive index of air n₁ =1, refractive index of water n₂ = 1.333, then the angle of refraction is
sinr = sini x (n₁/n₂)
Plug the values, we get
sinr = sin60 x (1/1.333)
sinr = 40.6°
The angle of refraction is less than angle of incidence due to refraction.
Thus, the angle of refraction is 40.6°
Learn more about Snell's law.
https://brainly.com/question/10112549
#SPJ2
factors that affect pressure in liquids
Answer:
Depth and density of the liquid determine the amount of pressure in a liquid.
Explanation:
Hello I need help with my science HW
Did you see a pattern in the ratios between mass and weight? Explain what you think this pattern means.
Answer:
please put a picture, i dont know what you are doing so i cant help.
Explanation:
If you want brainiest, can you help me?
Answer
?????
Explanation:
why does liquid have to cofficients of expansion
Answer:
The ratio of apparent increase in volume of the liquid per unit rise of temperature to the original volume is called its coefficient of apparent expansion. ... Thus a liquid has two coefficients of expansion. Measurement of the expansion of a liquid must account for the expansion of the container as well.
which best illustrates the relationships between a producer and a consumer
HELP ME ASAP PLZZZ!!!
In which reaction are the atoms of elements rearranged?
A 7 kg ball is push with a force of 28 N. What is the acceleration? .
Answer:
a = 4 m/s²
Explanation:
Given: 28 N, 7 kg
To find: Acceleration (a)
Solution: To find (a), divide force by weight
A = F ÷ m
= 28 ÷ 7
= 4 m/s²
Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.
PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
Answer:
Sam's average velocity for the entire walk is approximately;
0.075 km/min
Explanation:
The given parameters of the Lake Loop Trail are;
The distance of the trail Sam takes his dog to walk around = 5-km
From the table for the position and time, we have;
[tex]\begin{array}{ccc}Position \ (km) &&Time \ (min)\\0&&0\\1&&12\\2&&22\\3&&33\\4&&54\\5&&67\end{array}[/tex]
Plotting the given points gives the attached chart created with Microsoft Excel
The coordinates of the points are A(0,0), B(67, 5), C(67, 0)
By the definition of average velocity, we have;
[tex]Average \ velocity = \dfrac{Total \ distance}{Total \ time \ taken}[/tex]
From the plot of the points therefore, we have;
[tex]Average \ velocity= \dfrac{Length \ of BC}{The \ time \ elapsed \ between \ AC} = \dfrac{5 \ km - 0 \ km}{67 \ min - 0 \ min} = \dfrac{5 \ km}{67 \ min} \approx 0.075 \ km/min[/tex]Therefore;
Sam walked at an average velocity of approximately 0.075 km/min.
How do you calculate kinetic energy without velocity
The kinetic energy is calculated by work done, The work done is equal to the change in kinetic energy when the object is at rest.
Kinetic energy (KE) is calculated using the formula:
KE = (1/2) × mass × velocity²
However, if you don't have the velocity value, it is not possible to calculate the kinetic energy accurately. Velocity is a crucial component in determining kinetic energy because it quantifies the object's speed and direction of motion.
But there is a special case when the object is at rest the change in velocity is equal to the work done.
Therefore, The kinetic energy is calculated by work done, The work done is equal to the change in kinetic energy when the object is at rest.
To know more about kinetic energy:
https://brainly.com/question/999862
#SPJ6
Which statement best summarizes the development of the atomic theory over time?
Answer:
electrons move around nucleus in specific regions
We have that the correct statement that summarizes atoms over time will be
The discovery of new evidence resulted in changes to the atomic theory.
Option B
Generally
The Image shows that in the early 1800 the knowledge of atom was limited and it increased over time and by 1920 it had gone through a 4 stages of modifications to the atomic model
Atoms are solid spheresElectrons are attached to atom surfaceElectrons move around in the nucleus in a specificRapid motion of electrons in the cloudTherefore the correct statement that summarizes atoms over time will be
The discovery of new evidence resulted in changes to the atomic theory
For more information on this visit
https://brainly.com/question/17756498?referrer=searchResults
John has an object suspended in the air. It has a mass of 50 kilograms and is 50 meters above the ground. Calculate the object's potential energy?
it did work lollllllllllllllll
Answer:
Ok.............
hfjjjjjjlnggmm
When two chemical atoms form a chemical bond, the expected result is that the electrons
A.)will be in the excited state
B.) will be equal to the number of protons
C.) will complete a noble gas configuration in both atoms
D.) will be removed completely from both atoms
Answer:
B
Explanation:
atoms with equal or similar electronegativity form covalent bonds in which the valence electrons are shared between the two atom
During the formation of a chemical bond, the expected result is that the electrons will complete a noble gas configuration in both atoms. Hence, option (C) is correct.
The given problem is based on the concepts and fundamentals of chemical bonds. The chemical bonds between the two atomic species is formed by sharing the electrons.
When the electrons from each of the atom is shared, they maintain a strong intermolecular bond, which is known as chemical bond. This chemical bond allows the element to achieve noble gas configuration.The electrons that is shared within the two atomic species are known as shared pairs.The shared pairs are bonded within the atomic species by means of Van der Waals force of attraction as as covalent interaction..Thus, we can conclude that during the formation of a chemical bond, the expected result is that the electrons will complete a noble gas configuration in both atoms. Hence, option (C) is correct.
Learn more about the chemical bonds here:
https://brainly.com/question/23882847
A 1.70 m long string has a standing wave with 2 loops at a frequency of 38.4 Hz. What is the speed of the waves in the string? (Unit = m/s)
Answer:65.28
Explanation:
A long string has a standing wave with 2 loops at a frequency. The speed of the waves in the string is 65.28 m/s
What is frequency?The frequency is the number of cycles completed per second.
Given the length of the string l = is 1.70 m, no of loops n =2, frequency of wave f =38.4 Hz, then the speed of the waves is
f = nv /2l
Substitute the following values, we get
v = 38.4 x 2 x 1.70 / 2
v =65.28 m/s
Thus, the speed of the waves in the string is 65.28 m/s.
Learn more about frequency.
https://brainly.com/question/14316711
#SPJ2
What must happen to light in order for an image to form
A 15.0 cm object is 12.0 cm from a convex mirror that has a focal length of -6.0 cm. What is the height of the image produced by the mirror?
–5.0 cm
7.5 cm
-7.5 cm
5.0 cm
Answer:
-7.5
Explanation:
edge 2021
______________ controls the flow of electric current.
Answer!!!
Please
Answer:
Explanation:
Its resistor
Which image best illustrates diffraction?
Answer:
The first option- Sun shining through clouds
Explanation:
4 Suggest four ways in which participating in physical activities can build healthy relationship? 5.Show in two ways the influebces of values on the choices of goals you set as your life goal❤
Answer:
Increases levels of well-being neurotransmittersImproves fitnessImproves mental healthReduces the risk of developing diseasesExplanation:
Performing physical activities helps to build a healthy relationship with yourself, in the sense that physical activity promotes health at all levels. Health is a set of physical, mental and social well-being, so physical activity reaches all these levels and increases the quality of life for a person as a whole.
There are several types of physical activities that can be performed and you can choose the one that best fits your preferences and routine. A walk for example can be done in any safe place and at any time and it already helps in improving physical conditioning, in receiving serotonin and endorphins, in reducing blood pressure and protecting the heart and in improving mental health.
So the ideal is for each person to set their own goals in relation to their health and seek to achieve them, either to have a better quality of life, to socialize more with people, to prevent diseases, etc.
Physical exercise helps build relationship by:
Reducing one's stress and good level of mental health. One can be able handle anxiety and less mental health problem.What are Exercise?This is known to be any physical activities such as walking, running, etc., that is often done so as to keep the body fit.
It is very important when as it helps one to maintain a good balance of mental health. As a person moves their body, there is the release of endorphins that functions to make us feel good and helps handle the effects of stress and anxiety. The more a person exercise, the less mental health cases and more happier relationships.
Note that Values are the drive force of your actions and they push or motivate as you set your life goals. They help to eliminate any obstacle in term of foreign ideas that are against one's value and it keeps one's focus on the goal.
Learn more about Exercise from
https://brainly.com/question/1365564
xplain the difference between aerobic and anaerobic exercise and give 1 example of each?
Answer:
The term "aerobic" refers to the body's ability to provide energy through the use of oxygen. The term anaerobic refers to the body's ability to provide energy without the use of oxygen.
An example of an aerobic exercise is swimming. An example of an anaerobic exercise is sprinting.
Explanation:
Answer:
An example of an aerobic exercise is swimming. An example of an anaerobic exercise is sprinting.
Explanation:
3. A ray of monochromatic light (1 = 5.9 x 10-7 meters) traveling in air is
incident on an interface with a liquid at an angle of 45° as shown in
the diagram to the right. If the absolute index of refraction of the
liquid is 1.4, calculate the angle of refraction.
Answer:
45 degrees༼ つ ◕_◕ ༽つ
Explanation:
3. Neha travels 4 m towards the north, 3m towards the east, and then 7 m towards south, find the displacement and total distance traveled by her.
Answer:
Explanation:
Explanation: total displacement =3√2m. and total distance covered=14m. I hope this is right and helps u.
Objects traveling in! acceleration.* motion experience centripetal
Answer:
They travel
Explanation:
Because they move in a certin way