Answers
Answer:
[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]
Explanation:
The very first thing we can do here is to draw a sketch of the situation the problem is presenting. (See attached picture)
As you may see in the picture, we can suppose the spotlight is directly located on the ground so the light of the spotlight together with the person and the wall make two similar triangles.
In this case we need to think about the dimensions of the triangle that will change over time. We will call them:
x= distance between the spotlight and the man.
h= height of the shadow.
So we can build a relation between the height and the length of each triangle:
[tex]\frac{h}{12}=\frac{2}{x}[/tex]
the distance between the spotlight and the wall is constant, so I can directly write the 12 in my equation and the height of the man is constant as well, so I can write the 2 directly into the equation.
Next, we can solve the equation for h (since we are interested in figuring out how fast the height of the shadow is decreasing) so we get:
[tex]h=\frac{24}{x}[/tex]
So next, we need to take the derivative of the equation, since the derivative of a position function will give us the velocity at which that position is changing.
First we rewrite the equation like this:
[tex]h=24x^{-1}[/tex]
and take the derivative:
[tex]dh=-24x^{-2}dx[/tex]
we can rewrite the derivative like this:
[tex]\frac{dh}{dt}=-\frac{24}{x^{2}} \frac{dx}{dt}[/tex]
where:
dh/dt is the velocity at which the height of the shadow is decreasing (that's why our equation has a negative sign in front of it).
dx/dt is the velocity at which the value of x is increasing. In other words, how fast the man is moving away from the spotlight.
So we can go ahead and substitute:
we wish to find the velocity at which the shadow's height is decreasing when the distance between the man and the building is 4m, so in this case, x=12-4=8m
[tex]\frac{dh}{dt}=-\frac{24}{8^{2}}(1.1 m/s)[/tex]
so we get:
[tex]\frac{dh}{dt}=-0.4125 m/s[/tex]
Related Questions
Question 3 (1 point)
here were 2cars racing a quarter mile. The green car had a mass of 1200kg and crossed the finish line with a velocity of 53m/s. The red car had
a mass of 1100Kg and crossed the finish line with a velocity of 55m/s.,Which car had the great momentum?
Black car
Blue car
Green car
Red car
Answers
Answer:
The green car had the greatest momentum
Explanation:
Momentum
Momentum can be defined as "mass in motion" and is calculated as the product of the mass of the object by its velocity.
Being v the magnitude of the velocity and m the mass of the object, the momentum is calculated with:
p = mv
The green car had a mass of m1=1200 kg and crossed the finish line at v1=53 m/s. Hence, its momentum was:
p1 = 1200 Kg * 53 m/s = 63600 Kg.m/s
The red car had a mass of m2=1100 kg and crossed the finish line at v2=55 m/s. Hence, its momentum was:
p2 = 1100 Kg * 55 m/s = 60500 Kg.m/s
Since p1 > p2, then the green car had the greatest momentum
Why are some forms of speech not protected by the First Amendment?
because they support different religious views
because they could cause harm to others
because they criticize the government
because they are expressed in writing
Answers
Answer:
because they could cause harm to others
Explanation:
The "First Amendment" gives people the right to freedom of: religion, expression, press and assembly. However, the government has the right to censor one's speech if it could cause harm to others. Such speech falls under "unprotected category." This category includes the following: Defamation, Perjury, Blackmail, Plagiarism, True Threats, Child P.ornography, Obscenity, Solicitations to Commit Crime, Fighting Words, Incitement of Imminent Lawless Action. These forms of speeches are meant to harm other people, thus, they are not protected by the First Amendment.
Answer:
because they could cause physical harm to others
Explanation:
Took the test..
Bro help me
Explain how an object with a higher temperature can have less thermal energy than an object with a lower temperature. ASAP
Answers
The total energy of all the particles makes up thermal energy. This implies that larger objects with slower-moving particles at low temperatures can have more energy than smaller ones with higher temperatures.
What is thermal energy?Thermal energy is the sum of the energies of all the particles. This implies that larger objects at low temperatures can have more energy than smaller ones at higher temperatures due to slower-moving particles.
These molecules and atoms move more quickly when something is heated, providing it with more thermal energy. Compared to cold water, hot water has more thermal energy.
Therefore, molecules and atoms in colder objects move more slowly and have less thermal energy than those in warmer ones. The ability of particles to transfer energy increases with speed.
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1. What is the significance of the slopes of the two graphs?
2. Using the graphs, calculate the acceleration for each scenario?
3. What is the relationship between force, mass, and acceleration? Explain using data
Answers
Answer:
1. The velocity of the wagon decreases when Tradi is in the wagon because the mass increases while the external force stays constant.
2. The basic formula for calculating acceleration is a=F/a
Tommy along, acceleration: it will be 2.5 m/s^2. a=100/40
Tommy + Tradi = it will be about 1.66 m/s^2 since a=100/60
3. Well, you see, F=ma, when mass increases, the force decreases.
The relationship between mass and force is inversely proportional.
According to the graphs, velocity increases when there's less mass, which you could say that they are also inversely proportional.
Another comparison,
As the force applied on an object increases, when the mass stays constant, the acceleration also increases. Which means that they are directly proportional.
A skateboarder traveling at 10.4 m/s starts getting chased by a grumpy dog. The skateboarder speeds up with a constant acceleration for 39m over a 3.3s. We want to find the acceleration of the skateboarder over the 3.3s time interval. Which kinematic formula would be most useful to solve for the target unknown?
a. V= Vo+a(t)
b. X= (V+Vo/2)t
c. X= Vo(t)+1/2at^2
d. V^2 = Vo^2 +2ax
e. X= vt-1/2at^2
Answers
Answer:
c)X= Vo(t)+1/2at^2
Explanation:
From the question we are told that
initial speed u=10.4
displacement d= 39
time t=3.3s
accelaration a=?
Generally the best equation in solving for Acceleration is given to be
X= Vo(t)+1/2at^2
Mathematically
[tex]X= Vo(t)+1/2at^2[/tex]
[tex]39=10.4t+\frac{a}{2} *3.3^2[/tex]
[tex]5.445a=39-34.32[/tex]
[tex]a=39-34.32/5.445[/tex]
[tex]a=4.68/5.445[/tex]
[tex]a=0.86m/s^2[/tex]
please helppppppppppp
Answers
Answer: 4
Explanation:
when energy is greater then frequency should increase and wavelength should decrease.
Therefore answer is 4
the combined focal length of two thin lens is 24 cm and the focal length of one converging lens is 8
cm what is the focal length of the other
Answers
Answer: f = -12 cm
Explanation: Combined lenses is an array of simple lenses with a common axis. The combination is useful for correction of optical aberrations which cannot be corrected by simple lenses.
When two lenses are in contact and are thin, focal lengths are related as:
[tex]\frac{1}{F} =\frac{1}{f_{1}} +\frac{1}{f_{2}}[/tex]
If there is a distance between the lenses, the focal length will be:
[tex]\frac{1}{F} =\frac{1}{f_{1}} +\frac{1}{f_{2}} -\frac{d}{f_{1}f_{2}}[/tex]
Since the lenses in the question above are thin and in contact, the focal length of one of them will be:
[tex]\frac{1}{F} =\frac{1}{f_{1}} +\frac{1}{f_{2}}[/tex]
[tex]\frac{1}{f_{2}} =\frac{1}{f_{1}} -\frac{1}{F}[/tex]
[tex]\frac{1}{f_{2}} =\frac{1}{8} -\frac{1}{24}[/tex]
[tex]\frac{1}{f_{2}} =\frac{-2}{24}[/tex]
[tex]f_{2}=[/tex] -12
The focal length of the other lens is -12 cm, with the negative sign meaning it's a converging lens.
Which region contains the alkaline earth metal family of elements? A, B, C or D?
Answers
Answer:
B
Explanation:
B is the most likely region that contains alkaline earth family elements.
The alkaline earth metal family of elements is represented by B region in the figure.
What is alkaline earth metal?The alkaline earth metals are found on the periodic table in Group 2, which is on the far left side of the table between Group 1, the alkali metals, and Groups 3-12, the transition elements. This family is made up of six metals: beryllium, magnesium, calcium, strontium, barium, and radium.
What is periodic table?The periodic table, also known as the periodic table of the elements, is a tabular display of the chemical elements.
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detergents are used to clean the clothes why
Answers
Answer:Detergent mixes with water to remove dirt and oil from clothes. Water can't remove oil and dirt from clothes. Detergent cleans by causing a chemical reaction with water to force dirt and debris out of clothing. Detergents work with water to loosen the dirt trapped in the material of clothing and clean them away.
Explanation:May i plz have brainlist only if u wanna give me brainlist though have an nice day!
A solid sphere of radius R carries a fixed, uniformly distributed charge q. Obtain an expression for the magnitude of the electric field created by the sphere at a point P outside the sphere.
Answers
Answer:
The electric field outside the sphere will be [tex]\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex].
Explanation:
Given that,
Radius of solid sphere = R
Charge = q
According to figure,
Suppose r is the distance between the point P and center of sphere.
If [tex]\rho[/tex] be the volume charge density,
Then, the charge will be,
[tex]q=\rho\times\dfrac{4}{3}\pi R^3[/tex].....(I)
Consider a Gaussian surface of radius r.
We need to calculate the electric field outside the sphere
Using formula of electric field
[tex]\oint{\vec{E}\cdot \vec{dA}}=\dfrac{Q}{\epsilon_{0}}[/tex]
[tex]E\times4\pi r^2=\dfrac{\rho\dotc \dfrac{4}{3}\pi r^3}{\epsilon_{0}}[/tex]
Put the value from equation (I)
[tex]E\times4\pi r^2=\dfrac{qr^3}{\epsilon_{0}R^3}[/tex]
[tex]E=\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex]
Hence, The electric field outside the sphere will be [tex]\dfrac{qr}{4\pi\epsilon_{0}R^3}[/tex].
HELP ASAP!
Everything on screenshot.
Answers
Answer:
11. D
12. A
13. B
Explanation:
1. The surface where they slip is called the fault or fault plane.
2. identifying minerals. Hardness is determined by the ability of one mineral to scratch another. ... Each higher-numbered (harder) mineral will scratch any mineral with a lower number (softer).
3. The crust, the outermost layer, is rigid and very thin compared with the other two.The mantle, which contains more iron, magnesium, and calcium than the crust, is hotter and denser because temperature and pressure inside the Earth increase with depth.
How are energy and motion related?
Answers
Motion energy is indeed the total of kinetic and potential energies in a workable item. The energy contained in moving things is known as motion energy.
What is energy?In physics, energy is the capacity to accomplish work. It can be potential, kinetic, thermal, electric, chemical, radioactive, or in other forms. There is also heat and work, which is energy inside the process of being transferred through one body to the other. Energy is always classified according to its type once it has been transmitted.
The energy contained in moving things is known as motion energy, sometimes known as mechanical energy. More energy is saved when the thing goes quicker. Motion energy is indeed the total of kinetic and potential energies in a workable item.
Therefore, motion energy is indeed the total of kinetic and potential energies in a workable item.
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1| Page
01. (a) (i) What is Polarization of a matter
(ii) draw in atomic view before and after
Answers
Answer:
Polarization occurs when an electric field distorts the negative cloud of electrons around positive atomic nuclei in a direction opposite the field. Polarization P in its quantitative meaning is the amount of dipole moment p per unit volume V of a polarized material, P = p/V.
Explanation:
Answer:
Polarization occurs when an electric field distorts the negative cloud of electrons around positive atomic nuclei in a direction opposite the field. Polarization( P) in its quantitative meaning is the amount of dipole moment (p) per unit volume V of a polarized material, where P = p/V.
Find the applied voltage of a telephone circuit that draws 0.017A through a resistance Of 5,000 ohms
Answers
The first five harmonics for a vibrating string are shown in Figure24.13.a.For each harmonic, identify the number of wavelengths represented.b.For each harmonic, identify the number of nodes and antinodes that are present (include the ends of the string in your count).c.Which of the five harmonics has the highest natural frequency?d.Make a drawing that shows what the sixth harmonic would look like.
Answers
2nd: 1 wavelength. 3 nodes and 2 anti nodes
3rd: 1.5 wavelength. 4 nodes and 3 anti nodes
4th: 2 wavelengths. 5 nodes and 4 anti nodes
5th: 2.5 wavelengths. 6 nodes and 5 anti nodes
The 5th harmonic has the highest natural frequency out of these 5
Put a photo of the 6th harmonic in this post aswell
6. As the sky diver's fall the______energy is converted into _______.
a. Energy is created and destroyed.
b. Energy is created but not destroyed.
C. Energy is not created but is destroyed.
d. Energy is neither created nor destroyed.
Answers
Answer: B
D makes no sense because energy is created so we can remove that. C also makes no sense because if energy is not created how did it get destroyed if there's no energy in the first place. This leaves us with a and B the correct answer is B because energy is created and cannot be destroyed.
What average net force is required to accelerate a 3950 kg bus to a speed of 25m/s in 10.5 s?
Answers
Answer:
Explanation:
ACCELERATION = CHANGE IN VELOCITY
TIME TAKEN
∴ a = 25 - 0
10.5
∴ a = 50
21
by using f = ma,
we get , f = 3950 × 50
21
∴ A FORCE OF 9404.8 N IS NEEDED TO ACCELERATE A BUS OF 3950 KG.
please help me!!!!!!!!!!!!!!!
Answers
Answer:
3
Explanation:
i did it
4. What is the tan gential velocity of an object moving in a path of radius 2m with an angular velocity of
3rad/s.pls help me
Answers
Answer:
6m/s
Explanation:
The tangential velocity is the product of the linear velocity and the radius. This is expressed as;
v = wr
w is the angular velocity = 3rad/s
r is the radius = 2m
Substitute
v = 3 * 2
v = 6m/s
Hence the tangential velocity of the object is 6m/s
Trolley A, of mass 180 g, is moving at a velocity of 4 m/s towards trolley B
which is stationary and has a mass of 120 g. Trolley A then collides with
trolley B.
Calculate the speed of trolley B if:
i the collision is elastic (trolley A stops and trolley B moves off)
Answers
Answer:
To solve typical questions like this we can use law of conversation of linear momentum...which isT.I.L.M.=T.F.L.M.(Total initial linear momentum = total final linear momentum.)
Momentum = mass × velocity
T.I.L.M = T.F.L.M180×4 + 120×0 = 180×0 + 120×V
(180 ×4)/120 = V
6Ms^-1 = vWhich process causes Earth to act like a magnet?
O A. Convection of hot material in the mantle
O B. Flow of water due to gravitational energy
O C. Movement of ions in the core
O D. Shifting of the tectonic plates
SUBMI
Answers
Answer:movement of iron in core
Explanatio
Two points charge of 4\mu C and 2\mu C are placed at theopposite corners of a rectangle. What is the potential difference Va- Vb
Answers
Answer:
[tex]Va-Vb=168KV[/tex]
Explanation:
From the question we are told that
Two points charge of 4\mu C and 2\mu C
Generally we find the Va and Vb individually to find there difference
Given a rectangle with two equal sides each,Assume lengths for bot sides
Length L=0.3
Breath B=0.4
Diagonal D=[tex]\sqrt{0.3^2+0.4^2} =0.5[/tex]
at opposite sides
Mathematically Va can represented as
[tex]Va =k(\frac{4*10^_-_6}{0.3} +\frac{-2*10^_-_6}{0.5} )[/tex]
[tex]Va =9*10^9(\frac{4*10^_-_6}{0.3} +\frac{-2*10^_-_6}{0.5} )[/tex]
[tex]Va =9*10^9(0.00001333333-0.000004} )[/tex]
[tex]Va =84000V[/tex]
[tex]Va =84KV[/tex]
Mathematically Vb is represented as
[tex]Va =k(\frac{-4*10^_-_6}{0.3} +\frac{2*10^_-_6}{0.5} )[/tex]
[tex]Va =9*10^9(\frac{-4*10^_-_6}{0.3} +\frac{+2*10^_-_6}{0.5} )[/tex]
[tex]Va =9*10^9(-0.00001333333+0.000004} )[/tex]
[tex]Va =-84000V[/tex]
[tex]Va =-84KV[/tex]
Therefore
[tex]Va-Vb=84-(-84)\\Va-Vb=84+84\\Va-Vb=168KV[/tex]
a ballon is filled with air. what forces are acting on the ballon and the air?
Answers
Answer: Three forces act significantly on a freely floating helium-
filled balloon: gravity, air resistance (or drag force), and a
buoyant force.
Explanation:
The air pressure on the bottom of the balloon is slightly higher than the air pressure on the top of the balloon (because of the altitude difference). This difference gives rise to the bouyant force. This force competes with gravity as the two main forces acting on the balloon. Every time your feet hit the ground when you are running, the ground hits your feet with an equal and opposite force. Newton’s third law explains how balloons and rocket engines work. When the neck of an inflated balloon is released, the stretched rubber material pushes against the air in the balloon. The air rushes out of the neck of the balloon.
You push your friend, whose mass is 54kg, down a hill so she can go sledding. Her acceleration is 3m/s2. Calculate the amount of force you applied to your friend.
Answers
Answer:
18 newtons
Explanation:
Divide weight by speed
Waves transport
over distances.
A. solids
B.
liquids
C.
gases
D.
energy
Answers
Answer:
d)energy
Explanation:
Waves can transfer energy over distance without moving matter the entire distance. For example, an ocean wave can travel many kilometers without the water itself moving many kilometers. The water moves up and down—a motion known as a disturbance. It is the disturbance that travels in a wave, transferring energy.
physical science is the connection between
A. atoms and cells
B. energy and life
C. matter and rocks
D. matter and energy
Answers
Answer:
d d d d d d s d. d d d d d df ff f f. f f f r r ff f f ff d f f f f f f f f f r. ff r f. r
How can the relationship between atomic number and the number of protons be described?
Answers
Answer:
It's the number of protons in the nucleus of the atom
WILL GIVE BRAINLIEST TO THE CORRECT ANSWER
Estimate the net force needed to accelerate a 1000-kg car from rest.
AND
Estimate the weight of a 1000-kg car that is accelerating at 3m/s/s.
Answers
Answer:
See the answers below.
Explanation:
We can solve both problems using Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F =m*a
where:
F = force [N] (units of newtons)
m = mass = 1000 [kg]
a = acceleration = 3 [m/s²]
[tex]F = 1000*3\\F=3000[N][/tex]
And the weight of any body can be calculated by means of the mass product by gravitational acceleration.
[tex]W=m*g\\W=1000*9.81\\W=9810 [N][/tex]
What is constant of a spring if there is 150 j when stretched 0.25 m?
Answers
⚠️Please Help Me! I Need It Now!⚠️
Answers
Answer:
A. They are moving at 60 mph
Explanation:
When looking at the car on the track pass by, the people inside appear to be moving at the same speed as the car. So if the car is going 60 mph, the people instead will appear as though they are moving at 60 mph as well.