While standing at the edge of the roof of a building, a man throws a stone upward with an initial speed of 7.07 m/s. The stone subsequently falls to the ground, which is 19.3 m below the point were the stone leaves his hand. At what speed does the stone impact the ground? Ignore air resistance and use g = 9.81 m/s^2 for the acceleration due to gravity.

Answer:

The wavelength of the EM wave is 7.5 * 10⁻⁴ m

Explanation:

The velocity of a wave is related to its wavelength by the following formula;

velocity = wavelength * frequency

For an electromagnetic (EM) wave, its velocity is equal to the velocity of light, c = 3.0 * 10⁸ m/s

Given that the frequency and veloity of the given EM wave in the question is known, its wavelength is calculated as follows:

wavelength = velocity/frequency

where velocity of the EM wave = 3.0 * 10⁸ m/s;

frequency = 4THz = 4 * 10¹² Hz

wavelength = 3.0 * 10⁸m/s / 4 * 10¹² Hz

wavelength = 7.5 * 10⁻⁴ m

Therefore, the wavelength of the EM wave is 7.5 * 10⁻⁴ m

Answer:

The wavelength is 7.5 x 10^-5m

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]

Answer:

3947.7 kg/m³

Explanation:

The relativistic density can be calculated using below expression;

ρ = ρ' /[√( 1 - v²/c²)]

where,

ρ = Change in Density as a result of motion

ρ'= Actual density of cube

ρ' is given as = 1800 kg/m³

v = Velocity that the cube moves = 0.89c

c = Speed of light

c= 3×10^8 m/s

ρ = ρ' /[√( 1 - v²/c²)]

if we substitute the given values we have

ρ= 1800/ √ 〈1- 0.89c²/ c²〉

ρ=3947.7 kg/m³

Hence, the cube's density is 3947.7 kg/m³

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.

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.

Answer:

  2.5 m/s

Explanation:

We assume the skates are positioned so that the motion is essentially frictionless.

Conservation of momentum tells you Michelle's velocity (v) must satisfy ...

  ∑mv = 0

  (80 kg)(v) + (50 kg)(4 m/s) = 0

  v = -(50 kg)(4 m/s)/(80 kg) = -2.5 m/s

Michelle's speed is 2.5 m/s in the direction opposite Isabella's.

Answer:

2.5 m/s

Explanation:

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

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

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.

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

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.

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 .

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]

Answer:

a) Fg = -27.4 N

b) Fnet = 5.2 N

c) a = 1.9 m/s2

Explanation:

a)

       [tex]F_{g} = m*g = 2.8 kg*(-9.8m/s2) = -27.4 N (1)[/tex]

b)

       [tex]F_{net} = T -F_{g} = 32.6 N - 27.4 N = 5.2 N (2)[/tex]

c)

       [tex]a = \frac{F_{net} }{m} = \frac{5.2N}{2.8kg} = 1.9 m/s2 (3)[/tex]

Answer:

Liquid dishwashing soap

Vinegar

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)

No

because that is a light

The light travel faster in fresh water as compare to sea water.

Hence, the light travel faster in fresh water as compare to sea water.

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Answer:

Hope it may help you have a great day at school bye bye. Plz put it in brainliest answer my only request plz plz plz plz plz

Answer:

It you get a sushi for work, for a party, then it leads to people being happy, as an independant variable

It is changing the molecular structure of a protein

Explanation:

Answer:

well i am sure you need this to so look really hard at this then delete it

Explanation:

1. The speed with which electrons move through a copper wire is typically 10-4 m s-1

.

a. Explain why is it that the electrons cannot travel faster in the conductor?

b. Explain why the electron drift produces heat?

1. a) collisons with the crystal lattice atoms b) collisions with lattice atoms transfers energy.

2. Explain in terms of atomic and electron movement, why resistance increases with temperature.

2. Electrons drift through the lattice, as temperature increases the lattice atoms vibrate more and this increases the probability of

collision and hence resistance to electrons has increased.

3. Calculate the resistance of an aluminum (ρ = 2.8x10-8 Ωm) wire that is 2.0 m long and of circular cross section

with a diameter of 1.5 mm.

3. 32 mΩ

4. Determine the length of tungsten (ρ = 5.6x10-8 Ωm) wire with a diameter of 1.0 mm that is used to make a 20.0 Ω resistor.

4. 280 m

5. A nichrome (ρ = 100x10-8 Ωm) wire has a diameter of 0.40 mm. Calculate the length of this wire needed to carry a current

of 30 mA when there is a potential difference of 12 V across it.

5. 50 m

6. A thin copper (ρ = 1.68x10-8 Ωm, but you don’t need it) wire 200 cm in length has a 9 V dry cell connected between its ends.

Determine the voltage drop that occurs along 30 cm of this wire.

6. 1.35 V

7. If the potential difference across the bulb in a camping lantern is 9.0 V, what is the potential difference across the battery used to

power it?

battery gives the voltage of 9.0 V to the lantern to use it.

8. How much current, in amperes, is in a lightning stroke that lasts 0.05 second and transfers 100 coulombs?

I = q/t = (100 C)/(0.05 s) =2000 A

9. Calculate the resistance of the filament in a light bulb that carries 0.4 A when 3.0 V is impressed across it.

V = IR R = V/I = 7.5 Ω

10. Electric socks, popular in cold weather, have a 90-ohm heating element that is powered by a 9-volt battery.

How much current warms your feet?

V = I/R = 0.1 A

11. Calculate the current of a lightning bolt that delivers a charge of 35 coulombs to the ground in a time of 1/1000 second.

11. I = q/t = 35 000 A.

12. Calculate the current where 10 coulombs of charge pass a point in 5 seconds.

12. I = V/R = 2 A

13. Two light bulbs designed for 120-V use are rated at 40W and 60W. Which light bulb has the greater filament resistance? Why?

13. More current flows in the 60-W bulb, which means the resistance of the filament is less.

P = IV = V2/R, R = V2/P = (120 V)2/(60 W) = 240 Ω; for the 40-W lamp, R = (120 V)2/(40 W) = 360 Ω

14. A battery does 18 joules of work on 3 coulombs of charge. What voltage does it supply?

14. V= E/q= (18 J)/(3 C) = 6V

15. A power line with a resistance of 2 ohms has a current of 80 A in it. The power dissipated in the line is

15. 12800 W.

2

16. A toaster oven is plugged into an outlet that provides a voltage difference of 120 V.

What power does the oven use if the current is 10A?

16. P = IV = 1200 W

17. A VCR that is not playing still uses 10.0 W of power. What is the current if the VCR is plugged into a 120 V electric outlet? 17.

17. P = IV I = P/V = 0.083 A

18. A flashlight bulb uses 2.4 W of power when the current in the bulb is 0.8 A. What is the voltage difference?

18. P = IV V = P/I = 3V

19. A refrigerator operates on average for 10.0 h a day. If the power rating of the refrigerator is 700 W, how much electrical energy

does the refrigerator use in 1 day? (make sure to convert to kW)

19. E = Pt = (0.7 kW)(10.0 h) = 7 kWhours

20. A TV with a power rating of 200 W uses 0.8 kWh in one day. For how many hours was the TV on during this day?

20. E = Pt t = E/P= 0.8 kWh/0.2 kW = 4 h

21. Calculate the voltage difference in a circuit with a resistance of 25 Ω if the current in the circuit is 0.5 A.

21. V = IR = 12.5 V

22. A current of 0.5 A flows in a 60 W light bulb when the voltage difference between the ends of the filament is 120 V.

What is the resistance of the filament?

22. R = V/I = 240 Ω

23. A toy car with a resistance of 20 Ω is connected to a 3 V battery. How much current flows in the car?

23. I = V/R = 0.15 A

24. The current flowing in an appliance connected to a 120 V source is 2 A. How many kilowatt-hours of electrical energy does the

appliance use in 4 h? (2 equations used & convert watts to kW)

24. E = Pt P = IV = 0.24 kW E = 0.96 kWh

25. A calculator uses 9 V battery & draws 0.1 A of current. How much power does it use?

25. P = IV = 0.9 W

26. A battery causes 250 mA to flow when it is applied to a light bulb with a resistance of 50 ohms. How much current would flow if

the same source were applied to a 12 ohm resistor?

26. voltage of the source: V = IR = 12.5 V I = V/R = 1.04 A

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!                                                                                                      

Answer:

v = 4.0 m/s

Explanation:

       [tex]p_{f} = m_{w} * v_{w} + m_{g+w} *v_{g+w} = 0 (1)[/tex]

       [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]

Answer:

the answer is the third one since water reflects it

Explanation:

Answer:

The speed of stone while hitting the ground in all the three cases will be same .

Explanation:

The speed of stone while hitting the ground in all the three cases will be same .

They all will have same initial kinetic energy because they have same initial speed . Kinetic energy of an object does not depend upon the direction of velocity  of the object .

They will all gain kinetic energy due to loss of height .Since they all fall from the same height , gain of kinetic energy in all the three cases will also be same .

Hence final kinetic energy will be same when they hit the ground .

Hence they all have same speed while hitting the ground .

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.

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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