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The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points.

Explanation:

hope it helps!!

Driving a motor........

chemical energy is converted into kinetic energy.

Falling off of cliff

.........gravitational potential energy is converted into kinetic energy.

Hydroelectric energy generation

.......gravitational potential energy is converted into kinetic energy (i.e. driving a generator), which is then converted into electrical energy.

Nuclear power generation

.........mass is converted into energy, which then drives a steam turbine, which is then converted into electrical energy.

Answer:

40 because if it is the same weight then there is no weight to make the ride slower so it 40

Explanation:

Answer:

It will travel Vx * t = 30 m/s * 2 s = 60 m

Answer:

intensity

Explanation:

b. example, The sun is very bright and intense. and sounds can be very loud.

Answer:

hhhhhhhjjjkkllkcftkbgfjknhglncg

Answer:

[tex]\theta=30 \textdegree[/tex]

Explanation:

From the question we are told that:

Current [tex]I=2.0A[/tex]

Length [tex]L=0.60m[/tex]

Magnetic field [tex]B=0.30T[/tex]

Force [tex]F=0.18N[/tex]

Generally the equation for Force is mathematically given by

[tex]F = BIL sin\theta[/tex]

[tex]sin\theta=\frac{F}{BIL}[/tex]

[tex]\theta=sin^{-1}\frac{0.18}{0.3*2*0.6}[/tex]

[tex]\theta=30 \textdegree[/tex]

Answer:

100m

Explanation:

i think this is the answer because the formula for distance is

d=speed×time in this case the speed is 10m/s and the time is 10s therefore the distance will be

10m/s×10s

=100m

I hope this helps

Answer:

100 m

Explanation: this is when you need to find velocity and the formula for velocity is displacement by time taken.

Answer:

You should multiply 60 kg*9.8 and answer will come.

Hope this will help you.

Answer:

yes she is right you should multiple 60*9.8

have a great day God bless you

Answer:

1.5kg

Explanation:

Given data

mass m1= 2.5kg

mass m2=??

velocity of mass one v1= 1.5m/s

velocity of mass two v2= 4.1m/s

common velocity after impact v= 2.5m/s

Let us apply the formula for the conservation of linear momentum for inelastic collision

The expression is given as

m1v1+ m2v2= v(m1+m2)

substitute

2.5*1.5+ m2*4.1= 2.5(2.5+m2)

3.75+4.1m2= 6.25+2.5m2

collect like terms

3.75-6.25= 2.5m2-4.1m2

-2.5= -1.6m2

divide both sides by -1.6

m2= -2.5/-1.6

m2= 1.5 kg

Hence the second mass is 1.5kg

Answer:

in parallel combination : potential difference between two terminal of resistors are always constant. ... hence, potential difference ( voltage ) must be same across each resistor .

Explanation:

(C)

Explanation:

[tex]E = hf = (6.626×10^{-34}\:\text{J•s})(8.0×10^{15}\:\text{Hz})[/tex]

[tex]= 5.3×10^{-18}\:\text{J}[/tex]

Answer:

It's D

Explanation:

It's from alvs

Answer:

6.94 km/hr

Explanation:

m/s to km/hr -> Multiply by 18/5

25/(18/5)

=> 25 x 5/18

=> 125/18 km/hr

=> 6.94 km/hr

Answer: 90,000 m = 90 km

Explanation:

Given information

Time = 1 hour

Speed = 25 m/s

Given expression deducted from the given information

Distance = speed × time

Convert units of time

1 hour = 60 minutes

1 minute = 60 seconds

1 hour = 60 × 60 = 3600 seconds

Substitute values into the expression

Distance = 25 × 3600

Simplify by multiplication

Distance = [tex]\boxed{90,000 m=90km}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

Answer:

The diffraction grating separates light into colors as the light passes through the many fine slits of the grating. This is a transmission grating. ... The prism separates light into colors because each color passes through the prism at a different speed and angle.

Answer:

4√6 rad/s

Explanation:

Since the spring is initially stretched a length of x = 4 in when the 4 lb mass is placed on it, since it is in equilibrium, the spring force, F = kx equals the weight of the mass W = mg.

So, W = F

mg = kx where m = mass = 4lb, g = acceleration due to gravity = 32 ft/s², k = spring constant and x = equilibrium displacement of spring = 4 in = 4 in × 1ft /12 in = 1/3 ft

making k the spring constant subject of the formula, we have

k = mg/x

substituting the values of the variables into the equation, we have

k = mg/x  

k = 4 lb × 32 ft/s² ÷ 1/3 ft

k = 32 × 4 × 3

k = 384 lbft²/s²

Now, assuming there is no friction and no external force, we have an undamped system.

So, the natural frequency for an undamped system, ω = √(k/m) where k = spring constant = 384 lbft²/s² and m = mass = 4 lb

So, substituting the values of the variables into the equation, we have

ω = √(k/m)

ω = √(384 lbft²/s² ÷ 4 lb)

ω = √96

ω = √(16 × 6)

ω = √16 × √6

ω = 4√6 rad/s

2nd class leaver refers to such leaver in which load lies between effort and fulcrum.In a nut cracker too load is in between effort and fulcrum.Thus, nut cracker is a 2nd class leaver.......

Answer:

The metabolic power for starting flight=134.8W/kg

Explanation:

We are given that

Mass of starling, m=89 g=89/1000=0.089 kg

1 kg=1000 g

Power, P=12 W

Speed, v=11 m/s

We have to find the metabolic power for starting flight.

We know that

Metabolic power for starting flight=[tex]\frac{P}{m}[/tex]

Using the formula

Metabolic power for starting flight=[tex]\frac{12}{0.089}[/tex]

Metabolic power for starting flight=134.8W/kg

Hence, the metabolic power for starting flight=134.8W/kg

Answer: [tex]-5013.65\ J[/tex]

Explanation:

Given

No of moles [tex]n=3[/tex]

Temperature [tex]T=290\ K[/tex]

Initial volume [tex]V_1=2\ m^3[/tex]

Final volume [tex]V_2=1\ m^3[/tex]

Work done in constant temperature process is

[tex]W=nRT\ln \left(\dfrac{V_2}{V_1}\right)[/tex]

Insert the values

[tex]\Rightarrow W=3\times 8.314\times 290\ln \left (\dfrac{1}{2}\right)\\\\\Rightarrow W=-870\times 8.314\times \ln (2)\\\Rightarrow W=-5013.65\ J[/tex]

When the rock is suspended in the air, the net force on it is

∑ F₁ = T₁ - m₁g = 0

where T₁ is the magnitude of tension in the string and m₁g is the rock's weight. So

T₁ = m₁g = 37.8 N

When immersed in water, the tension reduces to T₂ = 32.0 N. The net force on the rock is then

∑ F₂ = T₂ + B₂ - m₁g = 0

where B₂ is the magnitude of the buoyant force. Then

B₂ = m₁g - T₂ = 37.8 N - 32.0 N = 5.8 N

B₂ is also the weight of the water that was displaced by submerging the rock. Let m₂ be the mass of the displaced water; then

5.8 N = m₂g   ==>   m₂ ≈ 0.592 kg

If one takes the density of water to be 1.00 g/cm³ = 1.00 × 10³ kg/m³, then the volume of water V that was displaced was

1.00 × 10³ kg/m³ = m₂/V   ==>   V ≈ 0.000592 m³ = 592 cm³

and this is also the volume of the rock.

When immersed in the unknown liquid, the tension reduces further to T₃ = 20.2 N, and so the net force on the rock is

∑ F₃ = T₃ + B₃ - m₁g = 0

which means the buoyant force is

B₃ = m₁g - T₃ = 37.8 N - 20.2 N = 17.6 N

The mass m₃ of the liquid displaced is then

17.6 N = m₃g   ==>   m₃ ≈ 1.80 kg

Then the density ρ of the unknown liquid is

ρ = m₃/V ≈ (1.80 kg)/(0.000592 m³) ≈ 3040 kg/m³ = 3.04 g/cm³

Answer:

0

Explanation:

The speed of the ball when it reaches the floor is 0 because any object at rest or in uniform motion has no speed or velocity

It stands for energy=mass times the speed of light squared.

Answer:

simple is rumple a daily ok I'll be

Answer:

Iceland lies on a boundary where two plates are moving away from each other. Heat from Earth’s interior rises through this plate boundary at a fast rate. This fact makes Iceland well-suited to producing electricity using its abundance of geothermal energy.

Explanation:

Edmentum sample answer.

Using the left-hand rule,

[tex](4\,\vec\imath+\vec k)\times(2\,\vec\imath+\vec\jmath-3\,\vec k) = \begin{vmatrix}\vec\imath&\vec\jmath&\vec k\\4&0&1\\2&1&-3\end{vmatrix} = -\vec\imath+14\,\vec\jmath+4\,\vec k[/tex]

Then in the right-handed rectangular coordinates, the cross product is the negative of this,

[tex]\boxed{\vec\imath-14\,\vec\jmath-4\,\vec k}[/tex]

The question is incomplete, the complete question is;

Light of frequency f falls on a metal surface and ejects electrons of maximum kinetic energy K by the photoelectric effect.

Part A If the frequency of this light is doubled, the maximum kinetic energy of the emitted electrons will be If the frequency of this light is doubled, the maximum kinetic energy of the emitted electrons will be

K/2.

K.

2K.

greater than 2K.

Answer:

2K

Explanation:

Given that the kinetic energy of photo electrons is given by;

K= E -Wo

Where;

K = kinetic energy

E= energy of incident photon

Wo = work function

But;

E= hf

Wo = fo

h= Plank's constant

f= frequency of incident photon

fo= Threshold frequency

So:

K= hf - hfo

Where the frequency of incident light is doubled;

K= 2hf - hfo

Hence, maximum kinetic energy of the emitted electrons in this case will be 2K

Answer:

B) The same as the momentum change of the heavier fragment.

Explanation:

Since the initial momentum of the system is zero, we have

0 = p + p' where p = momentum of lighter fragment = mv where m = mass of lighter fragment, v = velocity of lighter fragment, and p' = momentum of heavier fragment = m'v' where m = mass of heavier fragment = 25m and v = velocity of heavier fragment.

0 = p + p'

p = -p'

Since the initial momentum of each fragment is zero, the momentum change of lighter fragment Δp = final momentum - initial momentum = p - 0  = p

The momentum change of heavier fragment Δp' = final momentum - initial momentum = p' - 0 = p' - 0 = p'

Since p = -p' and Δp = p and Δp' = -p = p ⇒ Δp = Δp'

So, the magnitude of the momentum change of the lighter fragment is the same as that of the heavier fragment.  

So, option B is the answer

Answer:

a = 4m/s^2

Explanation:

Velocity(V) = uniform = 24m/s

time(t) = 6sec

Acceleration(a) = V/t

= 24/6

= 4m/s^2

When a sports car accelerates uniformly from rest to 24 m/s in 6 seconds,then acceleration of the car would be 4 m/s²

There are three equations of motion given by  Newton

The first equation is given as follows

v = u + at

the second equation is given as follows

S = ut + 1/2×a×t²

the third equation is given as follows

v² - u² = 2×a×s

Note that these equations are only valid for a uniform acceleration.

As given problem sport car accelerates uniformly from rest to 24 m/s in 6 seconds then the acceleration of the car can be calculated by using the first equation of motion

v = u + at

As given the initial velocity u= 0

The final velocity v = 24 m/s

The time taken is t= 6 seconds

By substituting the respective values of velocity and  time

24 = 0+ a*6

a = 24/6

a = 4 m/s²

Thus, when a sports car accelerates uniformly from rest to 24 m/s in 6 seconds,then acceleration of the car comes out to be 4 m/s²

Learn more about  equations of motion from here

brainly.com/question/5955789

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A roller coaster uses 800 000 J of energy to get to the top of the first hill. During this climb, it gains 500 000 J of potential energy and pauses for a fraction of a second at the very top before heading down the other side. At the top of the hill total, the kinetic energy of the roller coaster would be zero as the velocity is zero at the top of the hill, therefore the total mechanical energy is only because of potential energy.

Mechanical energy is the combination of all the energy in motion represented by total kinetic energy and the total stored energy in the system which is represented by total potential energy.

The expression for total mechanical energy is as follows

ME= KE+PE

As total mechanical energy is the sum of all the kinetic as well as potential energy stored in the system.As given in the problem a roller coaster uses 800000 J of energy to get to the top of the first hill. During this climb, it gains 500 000 J of potential energy which means 300000 J of energy is lost in the frictional energy while climbing the hill,

Thus at the top of the hill, the total energy of the roller coasters is only due to the potential energy.

Learn more about mechanical energy from here brainly.com/question/12319302

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Answer:

a. Find the graph in the attachment

b. 720 kΩ

c. The ratio V/I gives us our resistance which is 720 kΩ

Explanation:

a) plot a graph of V against I.

To plot the graph of V against I, we plot the corresponding points against each other. With the voltage V measured in volts and the current I measured in mA, the plotted graph is in the attachment.

b) Determine the wire's resistance , R.

The resistance of the wire is determined as the gradient of the graph.

R = ΔV/ΔI = (V₂ - V₁)/(I₂ - I₁)

Taking the first two corresponding measurements. V₁ = 72 V, I₁ = 0.1 mA, V₂ = 144 V and I₂ = 0.2 mA

R = (144 V - 72 V)/(0.2 - 0.1) mA

R = 72 V/0.1 mA

R = 72 V/(0.1 × 10⁻³ A)

R = 720 × 10³ V/A

R = 720 kΩ

c) State ohm's law and try to relate it your results.​

Ohm's law states that the current flowing through a conductor is directly proportional to the voltage across it provided the temperature and all other physical conditions remain constant.

Mathematically, V ∝ I

V = kI

V/I = k = R

Since the ratio V/I = constant, from our results, the ratio of V/I for each reading gives us the resistance. Since we have a linear relationship between V and I, the gradient of the graph is constant and for each value of V and I, the ratio V/I is constant. So, the ratio V/I gives us our resistance which is 720 kΩ.

Since V/I is constant, we thus verify Ohm's law.

Answer:

Accuracy is how much the consequence of an estimation adjusts to the right worth or a norm' and basically alludes to how close an estimation is to its concurred esteem

《OAmalaOHopeO》

Answer:

In a set of measurements, accuracy is closeness of the measurements to a specific value, while precision is the closeness of the measurements to each other.

Explanation:

_Hope it helps you_