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.
A ball is tied to the end of a length of string. A student holds one end of the string and whirls it so the ball travels in a vertical circle. First she whirls the ball at a very fast speed, and then she very gradually lowers the speed. Where is the ball most likely to be when the string begins to sag?
Answer:
The top of the circle
Explanation:
At the top of the circle, there are two forces pulling the ball towards the center of the circle: weight and tension.
∑F = ma
mg + T = mv²/r
As v goes down, T also goes down, until it eventually reaches 0.
At the bottom of the circle, weight is pulling down, or away from the center of the circle. Sum of the forces:
∑F = ma
T − mg = mv²/r
As v goes down, T also goes down. However, even at v=0, T cannot be less than mg.
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.
A 24.8 cm tall object is placed in front of a lens, which creates a -3.09 cm tall image. If the object is 37.5 cm from the lens, what is the image distance? pls help
Answer:
v = 4.67 m
Explanation:
It is given that,
Height of the object is 24.8 cm
Height of the formed image is -3.09 cm
Object distance is 37.5 cm, it is negative always
We need to find the image distance. Let v is the image distance. Magnification of an object is given by the formula as follows :
[tex]\dfrac{h'}{h}=\dfrac{v}{u}\\\\v=\dfrac{uh'}{h}\\\\v=\dfrac{-37.5\times (-3.09)}{24.8}\\\\v=4.67\ m[/tex]
So, the image is formed at a distance of 4.67 m.
Which shows a decrease in fluid pressure? A. Water in a creek slows down as it enters a slow-moving river. B. Oxygen is compressed as it is put into a pressurized tank. C. A river speeds up when it moves into a narrower channel. D. A fan is turned on high speed to low speed.
Answer:
Option D.
A fan is turned from high speed to low speed.
Explanation:
It is important to note that air is also a fluid.
In a system, static pressure of air increases with the speed of rotation of the fan. This is because when the speed of the fan is increased, the force with which it is pushing the air molecules is increased. Since pressure is a relationship between force and area, the pressure of the air molecules will be increased.
Conversely, when the speed of the fan is reduced, the priming force on the air molecules will be reduced, hence the pressure of the air will drop.
This makes option D the correct option
Answer:
A
Explanation
Becasue the water level is decreasing
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
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]
A deep-space satellite is sent to orbit a distant planet with unknown mass. On
arrival, the satellite begins its orbit and measures a gravitational pull from the
planet of 620 N. If the satellite has a mass of 450 kg and orbits the planet at a
radius of 4.0 x 10^6m, what is the approximate mass of the planet?(recall that G=6.7x10^-11 N•m2/kg^2.)
Answer:
The mass of the planet is [tex]3.29\times 10^{23}\ kg[/tex].
Explanation:
Given that,
The gravitational pull on the planet is 620 N
Mass of a satellite is, m₁ = 450 kg
Radius of a planet is [tex]4\times 10^6\ m[/tex]
We need to find the mass of the planet. Gravitational force is given by :
[tex]F=\dfrac{Gm_1m_2}{r^2}[/tex][tex]m_2[/tex] is the mass of the planet
[tex]m_2=\dfrac{Fr^2}{Gm_1}\\\\m_2=\dfrac{620\times (4\times 10^6)^2}{6.7\times 10^{-11}\times 450}\\\\m_2=3.29\times 10^{23}\ kg[/tex]
So, the mass of the planet is [tex]3.29\times 10^{23}\ kg[/tex].
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
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
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 would be the most reliable source for information about the toxicity of an industrial chemical?
a webpage on the internet with no sources listed
a brochure by a company that produces the chemical
a scientific journal article that is peer–reviewed
an opinion expressed by a chemistry professor
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)
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.
An ion has a charge of +3.2 x 1014 C. Another charge is brought near it and
experiences a repulsive electrostatic force. This other charge must be
Answer: Positive.
Explanation:
Given that the ion has a charge of +3.2 x 10^14 C.
When another charge is brought near it, it experiences a repulsive electrostatic force. The other charge brought near the ion must be positive.
This is because the electric field which is a region of space created by the positive ion with a charge of +3.2 x 1014 C have electric lines of force moving outward. Therefore, when another charge is brought near the positive ion, it will either attract or repel depending on the charge of the ion brought into the electric field created by the positive ion.
If the charge on the second ion is also positive, the electric lines of force will be in the same direction as that on the first ion and will their repel. However, if the second ion is negative, the electric field lines are in the opposite direction to that of the first positive ion, thereby creating an attractive electrostatic force in the electric field.
In summary, like charges repel, unlike charges attract.
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)
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
3. How do we measure the average kinetic motion of molecules in a solution?
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.'
plz help!!!
urgent!!
will give the brainliest!!!
Answer: Find the answer in the explanation.
Explanation:
I.) A piece of wire at room temperature.
The resistance of a piece of wire at room temperature is independent of both current and the voltage because it is an Ohmic component.
II.) Filament bulb
The filament wire in the filament bulb does not obey Ohms law.
For very small currents and voltage, the graph is roughly a straight line. At higher voltages, the line starts to curve.
III.) A diode is any component that allows electric current in only one direction. The resistance of a diode depends on the potential difference across it. Therefore, it does not obey Ohms law. It is a non-Ohmic component.
Find the attached files for the figures
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
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 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 lens is used to make an image of magnification -1.50. The image is 30.0 cm from the lens. What is the object’s distance (unit=cm)? PLS HELP
Answer: 20cm
Explanation:
Given the following data:
Magnification of image = - 1.50
Distance of image from the lens = 30.0cm
The Magnification of an image is the ratio of the image distance from the lens and the object distance from the lens.
Mathematically,
Magnification(M) = - (image distance (di) / object distance (do))
M = - (di/do)
-1.50 = - (30/do)
do = 30 / 1.5
do = 20 cm
Object is placed at a distance of 20cm from the lens.
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
learn more about kinetic energy
https://brainly.com/question/12669551?referrer=searchResults
#SPJ3
Erica throws a tennis ball against a wall, and it bounces back. Which force is responsible for sending the ball back to Erica?
OPTIONS :
A.) the force that the ball exerts on the wall
B.) the frictional force between the wall and the ball
C.) the acceleration of the ball as it approaches the wall
D.) the normal force that the wall exerts on the ball
Answer: D.) the normal force that the wall exerts on the ball
Explanation: The normal force acting on an object can be explained as a force experienced by an object when it comes in contact with a flat surface. The normal force acts perpendicular to the surface of contact.
In the scenario described above, Erica's tennis ball experiences an opposite reaction after hitting the wall.This is in relation to Newton's 3rd law of motion, which states that, For every action, there is an equal and opposite reaction.
The reaction force in this case is the normal force exerted on the ball by the wall perpendicular to the surface of contact.
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.
Rosa records the distance that a toy car rolls and the time it takes to cover the distance. What scientific practice is this? collecting data asking a question providing explanations communicating results
Answer:
collecting data
Explanation:
Data collection refers to a systematic method for gathering and analyzing information from a number of sources in order to provide a complete and reliable image of a subject region. The collection of data helps an individual or organization to answer specific questions, determine outcomes, and predicting future possibilities and outcomes. As per the question, rosa is collecting data about the distance and time of her toy car intrigued by the scientific query.
Answer:
A : Data
Explanation:
I’m doing the exam
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)
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:
The acceleration due to gravity on the moon is 1.67m/s. What does it mean?
Answer:
It actually is 1.67 m/s/s which means that if you are falling, the moon gravity will increase your falling velocity by 1.67 m/s every second.
If you are falling on the moon from a height. The speed at which you will be falling will increase by 1.67 m/s every second