Answer:
B light is produced by chemical change
Explanation:
im not the smartest but if you think about it, fireworks make bright lights. And what do they have: powders.
(but I still could wrong, sorry if I am)
The spectrum of a star shows a set of dark absorption lines equivalent to the absorption lines of the Sun but with one exception: Every line appears at a slightly longer wavelength, shifted toward the red end of the spectrum. What conclusion can be drawn from this observation
Answer:
The shift in the emission spectra of the relative velocity between the star and our planet, is called the relativistic doppler effect
Explanation:
The absorption and emission spectra are measured differently, the emission spectrum is the spectrum emitted by the star and the absorption spectrum is the absorption of these lines by the gases of our atmosphere, this absorption occurs for relatively broad Δλ.
The shift in the emission spectra of the relative velocity between the star and our planet, is called the relativistic doppler effect and has a red shift if the star moves away from us.
[tex]f_o = f_s \sqrt{\frac{1- v/c}{1 + v/c} }[/tex]
Does light travel faster in seawater or in fresh water? Does light travel faster in seawater or in fresh water? Light travels faster in seawater, because the index of refraction is smaller in seawater. Light travels faster in fresh water, because the index of refraction is smaller in fresh water. Light travels faster in fresh water, because the index of refraction is larger in fresh water. Light travels faster in seawater, because the index of refraction is larger in seawater.
No
because that is a light
The light travel faster in fresh water as compare to sea water.
When light goes from denser to rare medium the speed of light is increases.When light travel from rare to denser medium the speed of light is decreases.The reflective index of denser medium is more as compare to rare medium.The reflective index of sea water is more as compare to fresh water.Hence, the light travel faster in fresh water as compare to sea water.
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When an object falls, its:
A. PE increases and KE decreases.
B. PE does not change.
C. PE and KE both increase.
D. PE decreases and kE increases
Answer:
Option D. is correct.
Explanation:
The object's mechanical energy refers to the sum of the potential and kinetic energies of the object. When an object falls, its potential energy (PE) decreases, and its kinetic energy (KE) increases. The increase in kinetic energy is exactly equal to the decrease in potential energy.
Option D. is correct.
models are frequently used in science to assist in the understanding of complex information. Models can include items like a working volcano, and aquarium, or a stream table. What type of model are each of these items?
A) two dimensional
b) three dimensional
c) mental explanation
d) Computer simulation
A 45.0-kg girl stands on a 13.0-kg wagon holding two 18.0-kg weights. She throws the weights horizontally off the back of the wagon at a speed of 6.5 m/s relative to herself . Assuming that the wagon was at rest initially, what is the speed of the girl relative to the ground after she throws both weights at the same time
Answer:
v = 4.0 m/s
Explanation:
Assuming no external forces acting during the instant that the girl throws the weights, total momentum must be conserved.Since all the masses at rest initially, the initial momentum must be zero.So, due to momentum must keep constant, final momentum must be zero too, as follows:[tex]p_{f} = m_{w} * v_{w} + m_{g+w} *v_{g+w} = 0 (1)[/tex]
Assuming the direction towards the back of the wagon as positive, and replacing the masses in (1), we can solve for vg, as follows:[tex]v_{g+w} =- \frac{m_{w} *v_{w}}{m_{g+w} } = - \frac{36.0kg *6.5m/s}{58.0kg } = -4.0m/s (2)[/tex]
This means that the girl (along with the wagon on she is standing) will move at a speed of 4.0 m/s in an opposite direction to the one she threw the weights.Two people are playing tug-of-war. Due to their choice of footwear, theircoefficient of static friction is different. Participant 1 has a mass of 60 kg, acoefficient of static friction of 2.0, and can pull with a maximum force of1000 N. Participant 2 has a mass of 80 kg and a coefficient of staticfriction of 1.2, and can pull with a maximum force of 1200 N. Who wins?
Answer:
Participant 1 wins
Explanation:
Coefficient of static, μ = F/N, where F is the frictional force and N is the normal force.
The force exerted by each participant is the sum of the frictional force acting on each of them and the maximum force with which each participant pulls on the rope.
Frictional force, F = μ * N
Normal force, N = mass * acceleration due to gravity, g
For Participant 1; μ = 2.0, mass = 60 kg, g = 9.8 m/s²
Frictional force = 2.0 * 60 * 9.8 = 1176 N
Total force = (1176 + 1000) = 2176 N
For Participant 2; μ = 1.2, mass = 80 kg, g = 9.8 m/s²
Frictional force = 1.2 * 80 * 9.8 = 940.8N
Total force = (940.8 + 1200) N = 2140.8 N
From the values obtained above, Participant 1 exerts more force than Participant 2, therefore, Participant 1 wins
A 80 N force is needed to slide a 50.0 kg box across a flat surface at a constant velocity. What is the coefficient of kinetic friction between the box and the floor
Answer:
0.16
Explanation:
Given data
Force F= 80N
Mass m= 50kg
Reaction R= Weight= mg= 50*9.81= 490.5N
We know that
F=UR
Substitute and solve of U
U=F/R
U= 80/490.5
U=0.16
Hence the coefficient of friction is 0.16
You drive on Interstate 10 from San Antonio to Houston, half the time at 75 km/h and the other half at 106 km/h. On the way back you travel half the distance at 75 km/h and the other half at 106 km/h. What is your average speed (a) from San Antonio to Houston, (b) from Houston back to San Antonio, and (c) for the entire trip
Answer:
Explanation:
a ) from San Antonio to Houston let distance be d km .
Average speed = total distance / total time
time = distance / speed
Total time = (d / 2 x 75 ) +( d / 2 x 106 )
= .0067 d + .0047 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
b ) from Houston back to San Antonio
Total time = (d / 2 x 106 ) +( d / 2 x 75 )
= .0047 d + .0067 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
c )
For entire trip :
total distance = 2d
total time = 2 x .0114 d
Average speed = 2 d / 2 x .0114 d
= 87.72 km /h .
Suppose two skiers (A and B) are racing. Assume a frictionless surface! They start from the top of a mountain at the same time, and glide down to the flat area below. Just before the finish line there is a ditch. The skiers can either go down into the ditch or take a flat bridge over the ditch. Both the bridge and the ditch are covered with frictionless snow. Skier A decides to go down into the ditch. Skier B decides to go over the bridge. . Which skier gets to the finish line first, or do they arrive at the same time?
a. Skier A (ditch) arrives first
b. Skier B (bridge) arrives first
c. The skiers arrive at the same time
d. Neither skier arrives at the finish line
Answer:
b. Skier B (bridge) arrives first
Explanation:
This is because, skier B continues along the bring with the same velocity he started with before moving over the bridge and since the bridge is frictionless, he losses no kinetic energy and his speed is constant.
Whereas, skier A losses kinetic energy as he goes into the ditch. This is due to his change in potential energy. He thus emerges from the ditch with lesser kinetic energy than skier B and thus a slower speed.
Therefore, skier B arrives first since he moves at a constant speed.
Which two options are homogeneous mixtures?
A. Sand
B. A wet sponge
C. Liquid dishwashing soap
O D. Vinegar
Answer:
Liquid dishwashing soap
Vinegar
4. Taylor Swift pushes Kanye West,
headfirst fearless, off a high dive with and
initial speed of 6m/s. If the platform is 20m
high, what is Kanye's impact velocity with
the water? (velocity and angle)
Which of the following statements are true?
a. By convention, the direction of a current is taken to be the direction of flow for negative charges.
b. When an electric field is applied to a conductor, the free electrons move only in the direction opposite the applied electric field.
c. Current is the total amount of charge that passes through a conductor's full cross section at any point per unit of time.
d. In order to maintain a steady flow of current in a conductor, a steady force must be maintained on the mobile charges.
e. In a circuit, current is delivered by the positive terminal of a battery, and it is used up by the time it returns to the negative terminal of the battery.
Answer:
A, C, D and E are the true statement about current flowing.
Take 47 points. Hurry Someone save me just look the picture
Answer:
suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale. Denaturation, in biology, the process of modifying the molecular structure of a protein. Denaturation involves the breaking of many of the weak linkages, or bonds (e.g., hydrogen bonds), within a protein molecule that is responsible for the highly ordered structure of the protein in its natural (native) state.
Explanation:
hope this helps have a good rest of your day :) ❤
Explanation:
HW1. For example, suppose buying pizza for a work party leads to positive morale and to the work being done in half the time. Pizza is the independent variable, Work speed is the dependent variable, The mediator, the middle man without which there would be no connection, is positive morale.
HW2. The word denature means to render food unpleasant or dangerous to consume, it is denatured by adding a substance known as a denaturant. Aversive agents—primarily bitterants and pungent agents—are used to produce an unpleasant flavor.
Hope It Helps U
Please Mark As Brainl
Explain why objects in water appear to be a different size then the same objects above the water.
Answer:
the answer is the third one since water reflects it
Explanation:
Modify how could you charge the electric circuit shown below to allow lightbulb a to stay lit even if lightbulb b is removed from its base?
Marlon is studying a crab population. He has a large batch of crabs that were captured in the ocean. He places a plastic tag on a leg of each crab and releases the entire batch back into the ocean. The tags
include a phone number that can be called it the crabs are caught. For each crab, Marion records the location he released the crab and the location that it was recaptured. What can Marion measure with
this data
А
the speed the crabs traveled
B
the velocity the crabs traveled
the acceleration of the crabs
D
the displacement of the crabs
A 20.0 N force is necessary to stretch a spring 0.500 m. What is the spring constant of this spring?
The spring constant : k = 40 N/m
Further explanationGiven
Force = 20 N
The displacement of the spring=x=0.5 m
Required
The spring constant = k
Solution
Hooke's Law
F = k.x
k = F/x
Input the value :
k = 20/0.5
k = 40 N/m
You want to see how your new belt buckle matches your new hat. Your eyes are 114 mm below the top of the hat and 800 mm above the buckle. You walk up to your mirror and notice that the mirror is exactly large enough and exactly in the right position for you see both the top of the hat and the buckle.
1. What is the position of the top edge of the mirror relative to your eyes?2. How tall is the mirror?
Answer:
[tex]x=0.057m[/tex]
[tex]h=0.457m[/tex]
Explanation:
From the question we are told that
Distance of eyes from the top of hat [tex]d_1=114mm[/tex]
Distance of eyes from buckle [tex]d_2=800mm[/tex]
Generally position of mirror relative eyes x is mathematically given as
[tex]x=\frac{114}{2}[/tex]
[tex]x=57mm[/tex]
[tex]x=0.057m[/tex]
Generally the height of the mirror h is mathematically given as
[tex]h=\frac{(Buckle\ below\ the\ hat)+(Buckle\ below\ the\ hat)}{2}[/tex]
[tex]h=\frac{(114)+(800)}{2}[/tex]
[tex]h=457mm[/tex]
[tex]h=0.457m[/tex]
A traffic light consists of a horizontal member attached to a vertical support post. The horizontal member extends 7 m to the left of the support post and has a constant mass density of 15 kg/m. Each traffic light has mass of 10 kg, and the street sign has a mass of 4.5 kg. Make sure the connection between the horizontal member and the vertical support post is strong enough to withstand the forces exerted on the horizontal member. Calculate the effects of the forces resulting from the two traffic lights and the street sign on the horizontal member.
Answer:
τ = 539 N m
Explanation:
Let's use the rotational equilibrium relationship, where we set our reference system at the junction of the poles and the counterclockwise rotations we consider positive
τ = Σ τ_i
the mass of the traffic lights is m₁ = 10 kg, the mass of the sign m₂ = 4.5kg and suppose the worst case all the elements connected at the end (x = 7 m)
τ = 2 m₁ x + m₂ x + m₃ x / 2
we calculate the mass of the horizontal pole using the concept of linear density
λ = m₃ / l
m₃ = λ l
we substitute
τ = (2m₁ + m₂) x + λ l x / 2
τ = x (2m₁ + m₂ +λ l / 2)
let's calculate
τ = 7 (2 10 + 4.5 + 15 7/2)
τ = 539 N m
therefore, this is the torque that the joint between the two posts must resist
A hovercraft is being driven across a lake on a very windy day. The wind exerts a force of 5000 N north on the hovercraft. The propellers driving the hovercraft also exert a force.
What is the net force (to 3.s.f ) on the hovercraft when the force applied to the hovercraft by the propellers is: 10 000 N west
Answer:
The net force on the hovercraft is 11200 N.
Explanation:
Given;
force exerted on the hovercraft by wind, F₁ = 5000 N north
force exerted on the hovercraft by the propeller, F₂ = 10,000 N west
The net force on the hovercraft is calculated as;
[tex]F_{net} = \sqrt{F_1^2 + F_2^2} \\\\F_{net} = \sqrt{5000^2 + 10,000^2} \\\\F_{net} = 11180.34 \ N\\\\F_{net} = 11200 \ N \ (3.s.f)[/tex]
Therefore, the net force on the hovercraft is 11200 N.
PLEASE PLEASE PLEASE HELP
Answer:
just use y = mx + b to create an equation of the line in the graph.
then you can plug in 15 for x and then convert 1.5 hours into minutes and plug it in as well.
you dont even need to make an equation for a line. just add 0.2 for every 3 mins.
at 9, it's 0.6, so at 12 it would be 0.8, and then 15 it would be 1.0.
go again all way for 1. 5 hours.
Explanation:
the slope is 0.1/1.5 so you equation would be y = 0.1/1.5x
the slope is rise/run.
If the mass of a basketball is 18 times that of a tennis mass, can they ever have the same momentum? Explain your answer
Answer:
Yes
Explanation:
Yes. The momentum is the same when the speed of the tennis ball is 18 times greater than the speed of the basketball and the velocities of both objects are in the same direction.
An upward force of 32.6 N is applied via a string to lift a ball with a mass of 2.8 kg. (a) What is the gravitational force acting on the ball? (b) What is the net force acting upon the ball? (c) What is the acceleration of the ball?
Answer:
a) Fg = -27.4 N
b) Fnet = 5.2 N
c) a = 1.9 m/s2
Explanation:
a)
There are two forces acting on the ball, one directed upward (assuming this direction as positive, along the y-axis) which is the tension on the string (lifting force), and another aimed downward, which is the attractive force due to gravity.Applying the Newton's Universal Law of Gravitation to a mass close to the surface of the Earth (in this case the ball), we can take the acceleration due to gravity like a constant, that we call by convention g, equal to -9.8 m/s2.So, we can write the following expression for Fg:[tex]F_{g} = m*g = 2.8 kg*(-9.8m/s2) = -27.4 N (1)[/tex]
b)
The net force on the ball, will be just the difference between the lifting force (32.6 N) and the force due to gravity, Fg:[tex]F_{net} = T -F_{g} = 32.6 N - 27.4 N = 5.2 N (2)[/tex]
c)
According Newton's 2nd Law, the acceleration caused by a net force on a point mass (we can take the ball as one) is given by the following expression:[tex]a = \frac{F_{net} }{m} = \frac{5.2N}{2.8kg} = 1.9 m/s2 (3)[/tex]
The other name of eureka can
Answer:
I found it!
Explanation:
Answer:
Explanation:
displacement vessels
The can is filled to the top with water and the object placed in it. The volume of the object is equal to the volume of the water that is forced through the spout. Eureka cans are named after a scientist called Archimedes who first recorded this idea. They are sometimes also called displacement vessels.
A student drove to the university from her home and noted that the odometer reading of her car increased by 17.9 km. The trip took 26.6 min.
a) What was her average speed, in kilometers per hour?
b) IS she returned home by the same path 7 h 30 min after she left, what was her average speed and velocity for the entire trip?
Answer:
See calculation below
Explanation:
Average speed = Distance/Time
a) Given
Distance = 17.9km
Time = 26.6minutes
Time = 26.6/60 hr
Time = 0.443hr
Average speed = 17.9/0.443
Average speed = 40.38km/hr
b) If she returned home by the same path 7 h 30 min after she left, the distance will be the same;
Distance = 17.9km
Time = 7.5hr
Average speed = 17.9/7.5
Average speed = 2.387km/hr
Velocity of the entire trip = 40.38km/hr + 2.387km/hr
Velocity of the entire trip = 42.77km/hr
Hence the velocity of the entire trip is 42.77km/hr
Physical science-current can be increased by...
Option 3.) Increasing the voltage across the wire.
I know that the other answers are incorrect because, for one thing, the more resistance in a substance, the less flow of the current there is. Also, using a longer wire doesn't change anything, it just makes a electrical current go on longer. Lastly decreasing the voltage would make the current decrease in the atoms that flow through it to power an object.
-R3TR0 Z3R0
Which type of wall would make the best soundproofing for room?
A.
1.0 centimeter thick glass
OB.
two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them
C.
two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them
OD.
1.0 centimeter thick steel
Among the options given, the choice that would make the best soundproofing for a room is option C: two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them.
Soundproofing is achieved by reducing the transmission of sound waves from one side of the wall to the other. In this case, the combination of two layers of glass with a vacuum between them helps to reduce sound transmission effectively.
Glass is a denser material compared to air or vacuum, so it naturally provides some sound insulation. Adding an extra layer of glass creates a barrier that helps to further dampen sound vibrations. The vacuum between the glass layers acts as an additional sound barrier, as sound waves have difficulty propagating through a vacuum due to the absence of a medium for transmission.
On the other hand, a single layer of 1.0 centimeter thick glass (option A) or two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them (option B) would provide some sound reduction but not as effective as the combination of glass layers with a vacuum in option C.
1.0 centimeter thick steel (option D) would have high density and mass, which could help with sound insulation to some extent. However, steel can still transmit vibrations and might not be as effective as the combination of glass layers with a vacuum in option C for soundproofing a room.
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A fox locates its prey under the snow by slight sounds rodents make. The fox then leaps straight into the air, and then burrows its nose into the snow to catch its meal. If a fox jumps up to a height of 79 cm, calculate (a) the speed at which the fox leaves the snow, and (b) how long the fox is in the air. Ignore air resistance.m/s:s:You throw a baseball directly upward at time t = 0 at an initial speed of 12.9 m/s. What is the maximum height the ball reaches above where it leaves your hand? At what times does the ball pass through half the maximum height? Ignore air resistance and take g = 9.80 m/s2.Maximum height:Earlier time at half maximum height:Later time at half maximum height:
Answer:
1.a) 3.93 m/s
b) 0.80 s
2. a) 8.49 m
b) 0.39 s
Explanation:
1. a) The speed at which the fox leaves the snow can be found as follows:
[tex] v_{f}^{2} = v_{0}^{2} - 2gH [/tex]
Where:
g: is the gravity = 9.80 m/s²
[tex]v_{f}[/tex]: is the final speed = 0 (at the maximum height)
[tex]v_{0}[/tex]: is the initial speed =?
H: is the maximum height = 79 cm = 0.79 m
[tex] v_{0} = \sqrt{2gH} = \sqrt{2*9.80 m/s^{2}*0.79 m} = 3.93 m/s [/tex]
Hence, the speed at which the fox leaves the snow is 3.93 m/s.
b) The time at which the fox reaches the maximum height is given by:
[tex]v_{f} = v_{0} - gt[/tex]
[tex]t = \frac{v_{0} - v_{f}}{g} = \frac{3.93 m/s}{9.80 m/s^{2}} = 0.40 s[/tex]
Now, the time of flight is:
[tex] t_{v} = 2t = 2*0.40 s = 0.80 s [/tex]
2. a) The maximum height the ball reaches is:
[tex] H = \frac{v_{0}^{2} - v_{f}^{2}}{2g} = \frac{(12.9 m/s)^{2}}{2*9.80 m/s^{2}} = 8.49 m [/tex]
Then, the maximum height is 8.49 m.
b) The time at which the ball passes through half the maximum height is:
[tex]y_{f} = y_{0} + v_{0}t - \frac{1}{2}gt^{2}[/tex]
Taking y₀ = 0 and [tex]y_{f}[/tex] = 8.49/2 = 4.245 m we have:
[tex] 4.245 m -12.9m/s*t + \frac{1}{2}*9.80m/s^{2}*t^{2} = 0 [/tex]
By solving the above quadratic equation we have:
t = 0.39 s
Therefore, the time at which the ball passes through half the maximum height when the ball is going up is 0.39 s.
I hope it helps you!
5. (Liquids Gases) have particles with enough energy to spread out
throughoutcontainer. *
A)Liquids
B)Gases
Answer:
b gases
Explanation:
this is because gases spread out through out the entire container because they have no definite shape and are always moving.
During a phase change the temperature of a substance remains constant this is because during a phase heat changes the ____ energy of particles in a substance without changing their ____ energy
Answer:
Explanation:
individual and then net
hope that helps I could be wrong about this one though