Answer:
The acceleration of the car at the instant when t=3s is found by taking the gradient of the tangent at the point t=3.
The tangent are those dotted lines sloping upwards in the graph.
Tangent: A straight line that touches the curve and does not intersect it.
The reason why they wrote instantaneous is because the acceleration (or gradient of graph) is not constant throughout hence it is just at the moment when t=3s.
Gradient is used to find the acceleration of a speed time graph.
Compare and contrast electromagnetic force, electromagnetic waves, and an electromagnetic field
Electromagnetic fields are a combination of invisible electric and magnetic fields of force.
Electromagnetic waves is a way or path to represent electromagnetic field
When conductor comes in an Electromagnetic field the electromagnetic waves exerts a force on it called electromagnetic force
What are electromagnetic waves?Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field.
Electromagnetic fields are a combination of invisible electric and magnetic fields of force.
Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field. It is a way or path to represent electromagnetic field
When a conductor is placed in a magnetic field and current flows in the conductor, the magnetic field and the current interact each other to produce force. The force is called "Electromagnetic force". When conductor comes in an Electromagnetic field the electromagnetic waves exerts a force on it called electromagnetic force
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Which factor causes atmospheric pressure? A. Altitude above sea level. B. Weight of the atmosphere above the surface. C. Air currents in the atmosphere over the ocean. D. Sizes and shapes of clouds.
Answer:
B. Weight of the atmosphere above the surface.
Explanation:
The pressure that the atmosphere of the earth exerts is termed to be the atmospheric pressure. This pressure is applied on the surface of the air because of the gravitational pull. With the increase in altitude, the atmospheric pressure decreases. The atmospheric weight pushes itself downwards because of the gravity, this creates the pressure. The factor that causes atmospheric pressure is the 'Weight of the atmosphere above the surface.'
Which of the following quantities is a scalar?
A. 15 meters northwest
B. 7 meters per second south
C. 20 miles per hour
D. 13 inches to the left
Answer:
Option C
Explanation:
Scalar quantities are described by its magnitude only. They do not need to be described by the direction. So, 20 miles per hour is the scalar quantity.
Answer:
The answer is C
Explanation:
Scalar is a quantity that has only magnitude with no directions.
In the options above, option A, B and D show the directions which is Vector quantity.
ASSIGNMENTS
COURSES
Assignment
Attempt 1 of 3
SECTION 101
QUESTION 9 OF 35
A box is suspended from a series of cables as shown below. The angle of the cable attached to the ceiling is 30°
relative to the horizontal. The cable to the left has a tension force of 40 N. What is the approximate weight of the box?
30°
40N
23N
Answer:
23 N
Explanation:
By using the diagram above
[tex] \tan(30) = \frac{x}{40} [/tex]
By cross multiplying
[tex]x = \tan(30) \times 40[/tex]
[tex]x = 0.577 \times 40[/tex]
[tex]x = 0.577 \times 40[/tex]
[tex] x = 23.08[/tex]
[tex]approximately \: 23 [/tex]
The electromagnetic force that acts on the protons in the nucleus of an atom is _____ the strong nuclear force that acts on the same nucleus. Question 4 options: stronger than weaker than the same as approximately half
The electromagnetic force that acts on the protons in the nucleus of an atom is stronger than the strong nuclear force that acts on the same nucleus.
What is electromagnetic force?The current flows in the conductor, when a conductor is placed in a magnetic field. The magnetic field and the current both produce the magnetic force in that conductor. This force is known as the electromagnetic force.
The nuclear force is the force between the two nuclei. They both have positive charge. The force between them is weaker than the electromagnetic force which is the attractive force.
Thus, the electromagnetic force that acts on the protons in the nucleus of an atom is stronger than the strong nuclear force that acts on the same nucleus.
Learn more about electromagnetic force.
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Answer:
stronger than
Explanation:
took the mcq exam
Which of the following is the best thermal insulator
A. Air
B. Iron
C. Water
D. Aluminum
Answer: a. air
Explanation:
Generally, the lower the density of the material, the better insulator the material is: this is because in materials with very low density, particles are very spread apart, so they cannot collide with each other, and so the vibrations of the particles (which determine how hot a substance is) cannot be transmitted very efficiently.
In the options listed in this problem, air is the material with lowest density, therefore it is the best thermal insulator among them.
Answer:
A. Air
Explanation:
It is correct in Ареx.
The helium in the balloon has a mass of 0.00254 kg. The balloon has a volume of 0.0141 m3. Calculate the density of helium. Choose the correct unit from the box. m3 / kg kg / m3 kg m3
Answer:
Density (D) = 0.18014184397163 kg/m^3
Steps:
D = m / V
D= 0.00254 kg / 0.0141 M^3
D= 0.18014184397163 kg/m^3
Explanation:
Use this calculator for help and make sure to change the units on the right side. (can't use links in brainly but look up "Density Calculator calculator . net)
What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m? What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
Answer:
a) What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m?
5m/s
b) What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
40Hz
Explanation:
a) What is the wave speed of a wave that has a frequency of 50 Hz and a wavelength of 0.10 m?
Wave speed(v) = Frequency(f) × Wavelength (λ)
= 50Hz × 0.10m
=5m/s
b) What is the frequency of a wave that has a wave speed of 20 m/s and a wavelength of 0.50 m?
The formula for Frequency when given wave speed and wave length = Wave speed/ wave length
f = v/λ
Frequency = 20m/s ÷ 0.50m
Frequency = 40Hz
Answer:
40 Hz
Explanation:
A fire truck drives 3 miles to the east, then 1.2 miles to the west. What is the
displacement of the fire truck?
A. 4.2 miles east
B. 4.2 miles west
C. 4.2 miles
D. 1.8 miles east
Answer:
the answer is D. you have to go 3 miles to the east and then subtract the distance that the fire truck traveled to the the west.
Answer: D. 1.8 miles east
Explanation:
(Each "→" or "←" = .2 miles)
3 miles east: →→→→→ →→→→→ →→→→→
minus 1.2 miles west: ← ←←←←←
3 - 1.2 = 1.8 miles east: →→→→→ →→→→
Which of the following is true of an isothermal process?
O A. AU = 0
B. Volume is constant.
C. Temperature is constant.
O D. W = 0
Answer:
Isothermal process = Temperature is constant
Explanation:
As the name implies, iso means same and thermal is related to temperature. In isothermal process, the temperature of the system remains constant throughout. The exchange of heat takes place such that the thermal equilibrium is maintained.Hence, the correct option is (c) " temperature is constant".Answer:
A, C, & D
Explanation:
A. ΔU = 0
C. Temperature is constant
D. W = Q
a p e .x approved right answers
A graph titled Position versus Time shows time in seconds on the x axis, numbered 0 to 5, position in meters on the y axis, numbered 0 to 4. The graph has a horizontal line starting at (0, 3) to (5, 3). Given the information in the velocity vs. time graph, what is the displacement of the object after 1 second? m After 3 seconds? m After 5 seconds? m
Answer:
After 1 second: 3
After 3 seconds: 9
After 5 seconds: 15
Explanation:
You just multiply the time and velocity.
1 x 3 = 3, 3 x 3 = 9, etc.
Answer:
C.) The bicycle is not in motion.
Explanation:
A hollow, uniformly charged sphere has an inner radius of r1 = 0.105 m and an outer radius of r2 = 0.31 m. The sphere has a net charge of Q = 1.9 μC. What is the magnitude of the electric field, in newtons per coulomb, at a distance of r = 0.17 m from the center of the sphere?
Answer:
E = 77532.42N/C
Explanation:
In order to find the magnitude of the electric field for a point that is in between the inner radius and outer radius, you take into account the Gauss' law for the electric flux trough a spherical surface with radius r:
[tex]\int E\cdot dS=\frac{Q}{\epsilon_o}[/tex] (1)
Q: net charge of the hollow sphere = 1.9*10-6C
ε0: dielectric permittivity of vacuum = 8.85*10^-12 C^2/Nm^2
Furthermore, you have that the net charge contained in a sphere of radius r is:
[tex]Q=\rho V=\rho \frac{4\pi (r^3-r_1^3)}{3}[/tex] (2)
with the charge density is:
[tex]\rho=\frac{Q}{\frac{4}{3}\pi(r_2^3-r_1^3)}[/tex] (3)
r2: outer radius = 0.31m
r1: inner radius = 0.105m
The electric field trough the Gaussian surface is parallel to the normal to the surface, the, you have in the integral of the equation (1):
[tex]\int E\cdot dS=E(4\pi r^2)[/tex] (4)
where you have used the expression for a surface of a sphere.
Next, you replace the expressions of equations (2), (3) and (4) in the equation (1) and solve for E:
[tex]E(4\pi r^2)=\frac{1}{\epsilon_o}\frac{Q}{\frac{4}{3}\pi(r_2^3-r_1^3)}(\frac{4\pi (r^3-r_1^3)}{3})\\\\E=\frac{1}{\epsilon_o}\frac{Q(r^3-r_1^3)}{4\pi r^2(r_2^3-r_1^3)}[/tex]
you replace the values of all parameters, and with r = 0.17m
[tex]E=\frac{(1.6*10^{-6}C)((0.17m)^3-(0.105m)^3)}{4\pi(8.85*10^{-12}C^2/Nm^2)(0.17m)^2((0.31m)^3-(0.105m)^3)}\\\\E=77532.42\frac{N}{C}[/tex]
The magnitude of the electric field at a distance r=0.17m to the center of the hollow sphere is 77532.42N/C
A scientist wants to measure the relationship between humidity in the
summer and the number of home runs in baseball. Which of the following is a
testable question about this topic?
A. Are home runs more fun to watch than normal hits?
B. Are home runs more exciting during the summer?
C. Are there more home runs during the more humid months of the
summer?
D. Should fans like the players who hit the most home runs?
Answer:
i think option c is correct answer.
"Fun", "exciting", and "like" cannot be scientifically tested. They're perceived differently by different people, and they may even be perceived differently by the same person on different days.
Option-C is the only testable question on this list.
A camera lens focuses on an object 75.0 cm from the lens. The image forms 3.50 cm behind the lens. What is the magnification of the image?
Answer:
- 0.0466666667
Explanation:
We are told in the question above that:
A camera lens focuses on an object 75.0 cm from the lens. The image forms 3.50 cm behind the lens.
The formula for Magnification of an image = - image distance / object distance
Image distance = 3.50 cm
Object distance = 75 cm
Magnification = - 3.5/75
= -0.0466666667
= Approximately = -0.0467
Therefore, the magnification of the image is -0.0467
Answer:
0.557
Explanation:
That's the answer to a similar problem that asks us to solve for how tall the image is.
if it's 12.4 cm tall
correct for Acellus
This one:
A camera lens focuses on an image 78.0 cm from the lens
The image is 3.5 cm behind the lens
If it's 12.4 cm tall, how tall is the image
hope it helps
I have a test tomorrow and I can't find the definitions in my book so can you pls help me study by answering the following question? thnx! I will also mark the brainliest.
Answer:
See explanation
Explanation:
An element is a substance that cannot be chemically converted to another substance or broken down chemically into other substances.
Elements are represented by symbols. The symbol of an element may be the first one or two letters from its English or Latin name. For instance, the symbol of nitrogen is N. This symbol was derived from the first letter of its English name. The symbol for sodium is Na. This was derived from the first two letters of its Latin name, Natrium.
The periodic table is divided into horizontal rows called periods and vertical columns called groups. All members of the same period have the same number of electron shells while all members of the same group have the same number of valence electrons.
Metals are found towards the left hand side of the periodic table while non metals are found towards the right hand side of the periodic table. Metals looses electrons easily while nonmetals accepts electrons easily. Metals are good conductors of heat and electricity while non metals are poor conductors of heat and electricity.Metalloids have properties intermediate between those of metals and non metals and are found at the boarder line between metals and non metals in the periodic table. Metalloids include; silicon, boron, germanium, etc. The electrical conductivity of metalloids increases with temperature while the electrical conductivity of metals decreases with temperature.
1. Order the materials from smallest refractive index to largest refractive index.
Diamond
Glass
Quartz
Water
Air
Air = 1
Water = 1.33
Glass = 1.52
Quartz = 1.46
Diamond = 2.42
Order the materials from smallest refractive index to largest refractive index.
Air = 1
Water = 1.33
Glass = 1.52
Quartz = 1.46
Diamond = 2.42
What is refractive index?The refractive index or index of refraction is the ratio of speed of light in
Quartz = 1.46vacuum and speed of light in medium.
The highest refractive index is of diamond and minimum is for air.
The order of refractive index is
Air = 1
Water = 1.33
Glass = 1.52
Quartz = 1.46
Diamond = 2.42
Hence, the order is listed above.
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Question is in the uploaded photo
Answer:
1) Mass of the string = 0.0267kg
Explanation:
1) In the above question, we are given:
Length of guitar string = 60cm
Wave speed = 30.0m/s
Tension = 50N
9.81 N = 1 kg
50N = 50/9.81
= 5.10kg
We have the formula
v = √(F/μ)
Where F = the tension in the string in newtons,
v = the wave speed in m/s
μ = the mass per unit length of the string in kg/m
The formula for μ is derived as
v = √(F/μ)
Square both sides
v² = [√(F/μ)]²
v² = F/μ
μ = F/v²
From the question,
μ = 40/ 30.0²
μ = 0.044kg/m
To calculate the mass of the string we use the formula
μ = Mt / Lt = total mass/total length.
Total length = 60cm
In meters = 0.60m
0.044kg/m = Mt/ 0.60m
Mt = 0.0266666667kg
Mass of the string = Approximately 0.0267kg
2)
Which optical devices spread light apart?
A. A and B
B. A and D
C. B and D
D. B and C
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Optical Devices.
Now basically here the devices that can spread light over apart are the CONCAVE LENS and Convex mirror.
so the Answer is
C. B and D
The optical devices that spread light apart is B and D.
What are optical devices?Optical devices are implements or instruments that process,analyses light waves and interprete it in order to enhance an image for visibility and determine the features of such image.
Therefore, The optical devices that spread light apart is B and D.
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At which point does the planet have the least gravitational force acting on it?
Answer:
At which point does the planet have the least gravitational force acting on it?
Explanation:
In an elliptical orbit, when a planet is at its furthest point from the Sun, it is under the least amount of gravity, meaning that the force of gravity is strongest when it is closest.
Answer:
Point A
Explanation:
Recall that gravitational force is inversely proportional to the square of the distance between the 2 objects.
This means that the farther away the objects are from each other, the lesser their gravitational interaction will be.
In this case we can see that Point A is furthest away from the star, hence this will be the location with the least gravitational force from the star.
which of the following does not negatively affect the health of a watershed? A. Surface runoff from roads, sidewalks, and roofs. B. Sewer overflow from combined sewer systems. C. Wilderness areas. D. Chemicals used on farmland.
Answer:
A. Surface runoff from roads, sidewalks, and roofs
C. Wilderness areas. will mostly likely not affect the health of watershed
Explanation:
Options A and C are not really harmful to the health of watershed, but chemicals used on farmlands and overflow from combined sewer systems can contaminate watershed adversely, which can be a major cause of the cholera outbreak (a water borne disease)
If an electromagnetic wave has a frequency of 4.5 x 1018 Hz, what is its
wavelength? Use î=”. The speed of light is 3 * 108 m/s.
A. 1.5 x 10-26
B. 6.7 x 1026 m
C. 1.5 x 10-10 m
D. 6.7 * 10-11 m
Answer:
Wavelength of electromagnetic wave = 6.7 × 10⁻¹¹
Explanation:
Given:
Frequency of electromagnetic wave = 4.5 × 10¹⁸ Hz
Speed of light = 3 × 10⁸ m/s
Find:
Wavelength of electromagnetic wave
Computation:
⇒ Wavelength = Speed of light / Frequency
⇒ Wavelength of electromagnetic wave = 3 × 10⁸ / 4.5 × 10¹⁸
⇒ Wavelength of electromagnetic wave = 0.67 × 10⁻¹⁰
Wavelength of electromagnetic wave = 6.7 × 10⁻¹¹
TP-35 How many minutes should a blower be operated before starting an engine?
Answer:
The required minutes is 4 minutes.
Explanation:
Blowers are very important or Crucial because it's safeguard life on boat.
Blowers are constructed so that gasoline fumes will be cleared from comparments.
It is important to operate the blower for 4 minutes before starting an engine to remove fuel vapor so as to prevent explosion because explosive gasoline's or battery fumes could be present in engine compartments which could cause explosion if it's not operated for 4 minutes before you start the engine
How do our actions as a family, impact the environment?
Human impact the environment in positive and negative ways.Cutting down trees and littering have a negative effect on animals and plants. Protecting endangered species and cleaning lakes and seas has a positive effect on the environment.
The lack of ________ between the train and the tracks allow the train to reach unbelievable speed.
Answer:
Friction
Explanation:
Friction is the force that is created when two objects rub against each other. All objects are rough, even though it might not appear that way, on the microscopic scale. These little grooves and ridges get stuck against each other when two objects are moved against each other, and they slow down motion. If there is no friction between a train and its tracks, then it can continue to accelerate without slowing down. Hope this helps!
A stone was projected at an angle of 40o and initial velocity of 20m/s. (a.)Determine the time of flight (b)Maximum height.
Answer:
A.) 1.3 seconds
B.) 0.42 m
Explanation:
A.) You are given the angle of projection to be 40 degrees and initial velocity of 20m/s.
At vertical component
U = Usin 40 that is,
U = 20sin40
Using the first equation of motion under gravity
V = U - gt
Let V = 0
0 = UsinØ - gt
gt = UsinØ
t = UsinØ/g
Where U = 20 m/s
Ø = 40 degree
g = 9.8 m/s^2
Substitutes all the parameters into the formula
t = 20sin40/9.8
t = 1.3 seconds
Total time of flight T = 2t
T = 2 × 1.3 = 2.6 s
B.) To calculate the maximum height,
You will use the formula
V^2 = U^2 - 2gH
At maximum height, V = 0
2gH = Usin^2Ø
H = Usin^2Ø/ 2g
Substitutes all the parameters into the formula
H = 20 sin^2(40) ÷ 2(9.8)
H = 8.2635/19.6
H = 0.42 m
A rope exerts a force F on a 20.0-kg crate. The crate starts from rest and accelerates upward at 5.00 m/s2 near the surface of the earth. What is the kinetic energy (in J) of the crate when it is 4.0 m above the floor?
Answer:
400 J
Explanation:
Given:
Δy = 4.00 m
v₀ = 0 m/s
a = 5.00 m/s²
Find: v²
v² = v₀² + 2aΔy
v² = (0 m/s)² + 2 (5.00 m/s²) (4.00 m)
v² = 40.0 m²/s²
Find KE:
KE = ½ mv²
KE = ½ (20.0 kg) (40.0 m²/s²)
KE = 400 J
The kinetic energy of the object is the energy is that energy which possesses due to the its motion. It is the work needed to accelerate a body of a given mass from rest to its stated velocity .
Kinetic energy (KE) = 1/2 *m* v^2
mass = 20 kg (given )
accelerates = a = 5 m/s^2
to find = v ?
u = 0
using newton's kinematics equation
v^2 - u^2 = 2as
v^2 - 0 = 2 * (5) * (4)
v^2 = 40
v = [tex]\sqrt{40}[/tex] m/s
Kinetic energy (KE) = 1/2 *m* v^2
= 1/2 * (20 kg) * 40 m/s
= 400 J
The kinetic energy (in J) of the crate when it is 4.0 m above the floor will be 400 J
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3. How do we measure the average kinetic motion of molecules in a solution?
WILL MARK BRAINLIEST ANSWER WITHIN HALF AN HOUR!! How did Faraday’s invention of the motor and the generator, explain that electricity and magnetism are related? (Answer in complete sentences.)
Explanation:
1. He discovered electromagnetic induction
Before Faraday made it on the scene, scientists were aware of electricity, though they had done little to harness it for practical use. Take Giovanni Aldini, for example, who embarked on a tour around Europe in 1803 to electrocute a corpse in front of an audience. Electricity was such a mysterious force at the time, most laypeople saw it akin to magic more than anything else.
Faraday changed all that when he discovered electromagnetic induction in 1831. Through his innovative experiments, he found that by placing a conductor in a changing magnetic field, it would produce voltage across the conductor. In simpler terms? He found a way to cause an electric current, and that discovery was later applied to many devices we use today.
2. His inventions transformed the home, farm, and factory
Forget about that fancy fridge that produces three different types of ice cubes on a whim. Before the advent of harnessable electricity, nearly every facet of human life functioned differently than it does now. People in Faraday’s time got by at home with oil lamps, wooden ice boxes, and coal stoves by dry sinks.
Faraday’s discoveries also came to revolutionize work for small-time farmers in just about every way imaginable. Electricity eliminated manual labor like pumping water, so that rural families no longer spent hours of their day hauling water to livestock or to the house. Automated systems for tasks like milking cows kept farmers from crippling their hands, and the threat of barn fires from knocked over oil lamps during early-morning milking decreased. And although the industrial revolution was already underway when Faraway was born, cotton gins and power looms became old news as marvels like sewing machines and the telegraph refashioned the ways people worked and communicated. From cell phones to air conditioning, the modern conveniences we now take for granted were once but a fantasy without Faraday’s relentless wonder and curiosity to fuel them.
Keep your promise and mark me BRAINLIEST if you want..
What happens to the object if the line crosses the x-axis from the positive portion of a velocity versus time diagram?
Answer:
A velocity time graph shows the change of velocity of an object with respect ot time. If the slope of the graph is increasing in the postive region, it means that the velocity is changing, if the slope is decreasing, it means the the velocity is decreasing, but the object is moving in the same direction (positve direction).
If this slope intersects the graph at x-axis, it means that the body has 0 velocity and has become still. After that, if the line enters in the negative region, it means that its velocity is started to increases again, but the body is movinging in the opposite direction (negative direction)
HEEELLPP!! SEND HELP!! Sometimes goals need to be changed. What are some possible reasons for this?