An ice skater with a mass of 50 kg is gliding acrossthe ice at a speed of 8 m/s when herfriend comes up from behind and gives her a push,causing her speed to increase to 12m/s. How much work did the friend do on the skater

Answers

Answer 1

Answer:

[tex]W=2KJ[/tex]

Explanation:

From the question we are told that:

Mass [tex]M=50kg[/tex]

Initial Velocity [tex]v_1=8m/s[/tex]

Final Velocity [tex]v_2=12m/s[/tex]

Generally the equation for Work-done is mathematically given by

W=\triangle K.E

Therefore

 [tex]W=0.5M(v_2^2-v_1^2)[/tex]

 [tex]W=0.5*50(12^2-8^2)[/tex]

 [tex]W=2KJ[/tex]


Related Questions

when blueshift occurs,the preceived frequency of the wave would be?​

Answers

Answer:

When blueshift happens, the perceived frequency of the wave would be higher than the actual frequency.

Explanation:

As the name suggests, when blueshift happens to electromagnetic waves, the frequency of the observed wave would shift towards the blue (high-frequency) end of the visible spectrum. Hence, there would be an increase to the apparent frequency of the wave.

Blueshifts happens when the source of the wave and the observer are moving closer towards one another.

Assume that the wave is of frequency [tex]f\; {\rm Hz}[/tex] at the source. In other words, the source of the wave sends out a peak after every [tex](1/f)\; {\text{seconds}}[/tex].

Assume that the distance between the observer and the source of the wave is fixed. It would then take a fixed amount of time for each peak from the source to reach the observer.

The source of this wave sends out a peak after each period of [tex](1/f)\; {\text{seconds}}[/tex]. It would appear to the observer that consecutive peaks arrive every [tex](1/f)\; {\text{seconds}}\![/tex]. That would correspond to a frequency of [tex]f\; {\rm Hz}[/tex].

On the other hand, for a blueshift to be observed, the source of the wave needs to move towards the observer. Assume that the two are moving towards one another at a constant speed of [tex]v \; {\rm m \cdot s^{-1}}[/tex].

Again, the source of this wave would send out a peak after each period of [tex](1/f)\; {\text{seconds}}[/tex]. However, by the time the source sends out the second peak, the source would have been [tex]v \cdot (1 / f) \; { \rm m}= (v / f)\; {\rm m}[/tex] closer to the observer then when the source sent out the first peak.

When compared to the first peak, the second peak would need to travel a slightly shorter distance before it reach the observer. Hence, from the perspective of the observer, the time difference between the first and the second peak would be shorter than [tex](1/f)\; {\text{seconds}}[/tex]. The observed frequency of this wave would be larger than the original [tex]f\; {\rm Hz}[/tex].

g Consider a mass-spring system where the spring constant is 5 N/m and the mass on the spring is 0.5 kg. The mass is moved a distance of -0.9 m from its equilibrium position. How much work is done by the spring

Answers

Answer:

The work done by the spring is 2.025 J

Explanation:

Given;

mass on the spring, m = 0.5 kg

spring constant, k = 5 N/m

extension of the spring, x = 0.9 m

The work done by the spring is calculated as;

[tex]W = \frac{1}{2} kx^2\\\\W = \frac{1}{2} \times 5 \times (0.9)^2\\\\W = 2.025 \ J[/tex]

Therefore, the work done by the spring is 2.025 J

1. Which one of the following is not an organic compound? Why? CH4 C2H6O CaO
2. Fill in the chart below to identify and describe the functional groups associated with organic chemistry. Name General Structure Properties/Uses Alcohol Aldehyde Ketone Fatty acid Ether
3. Explain why carbon is called “the backbone” molecule of organic chemistry and why organic molecules couldn't easily be based on H or O instead.

Answers

Answer:

1. CaO is not an organic compound because it doesn’t contain a carbon molecule.

2.

Name General Structure Properties/Uses

Alcohol R-OH (contains a hydroxyl group)  Can be poisonous, can be made from fermentation or distillation

Aldehyde R-COH (contains a carbon atom double-bonded to an oxygen and single-bonded to a hydrogen)  Makes up formaldehyde and acetaldehyde

Ketone R-CO-R (contains a carbon atom double-bonded to an oxygen atom and then connected to carbon chains through the other two single bonds)   Makes up acetone

Fatty acid R-COOH (contains a carbon atom double-bonded to an oxygen atom, single-bonded to a hydroxyl, and single-bonded to the carbon chain) Makes up fatty acids like acetic acid and stearic acid; used to form esters

Ether R-O-R (contains double carbon chains connected to an oxygen atom through single bonds)   Ethyl ether is very volatile and flammable, used in veterinary medicine

3. Carbon is able to make four covalent bonds with other elements. This gives it a lot of diversity and the ability to form differently shaped molecules that perform specific functions or fit specific cell receptors in the body. H can form only one bond, and oxygen forms only two bonds, so they don't have as much potential to form a good starting point for organic molecules.

Explanation:

pf

CaO is not an organic compound because it doesn’t contain a carbon molecule.

Name General Structure Properties/Uses

(which contains a hydroxyl group)  Can be poisonous, can be made from fermentation or distillation

Aldehyde R-COH (contains a carbon atom double-bonded to oxygen and single-bonded to hydrogen)  Makes up formaldehyde and acetaldehyde

Ketone R-CO-1R (contains a carbon atom double-bonded to an oxygen atom and then connected to carbon chains through the other two single bonds)   Makes up acetone

Fatty acid R-COOH (contains a carbon atom double-bonded to an oxygen atom, single-bonded to a hydroxyl, and single-bonded to the carbon chain) Makes up fatty acids like acetic acid and stearic acid; used to form esters11

Ether -O-R (contains double carbon chains connected to an oxygen atom through single bonds)   Ethyl ether is very volatile and flammable, used in veterinary medicine

Carbon can make four covalent bonds with other elements. This gives it a lot of diversity and the ability to form differently shaped molecules that perform specific functions or fit specific cell receptors in the body. H can form only one bond, and oxygen forms only two bonds, so they don't have as much potential to form a good starting point for organic molecules.

Learn more about organic molecules.

https://brainly.com/question/24225576

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true or false A permanent magnet and a coil of wire carrying a current both produce magnetic fields

Answers

Answer:

True. A permanent magnet like the earth produces its own B field due to movement of the iron core. The earths magnetic field is the reason why we have an atmosphere and it also is the only defense against solar flares. A coil of wire or solenoid that has current have so much moving charge that the motion of the electrical charge can create a significant G b-field

how can scientific method solve real world problems examples

Answers

The scientific method is nothing more than a process for discovering answers. While the name refers to “science,” this method of problem solving can be used for any type of problem

The working substance of a certain Carnot engine is 1.50 mol of an ideal monatomic gas. During the isothermal expansion portion of this engine's cycle, the volume of the gas doubles, while during the adiabatic expansion the volume increases by a factor of 5.7. The work output of the engine is 940 J in each cycle. Compute the temperatures of the two reservoirs between which this engine
operates.

Answers

Answer:

The hot temperature is 157.5 K

The cold temperature is 48.8 K

Explanation:

Step 1: Data given

The working substance of a certain Carnot engine is 1.50 mol of an ideal monatomic gas.

The volume increases by a factor of 5.7

The work output of the engine is 940 J in each cycle.

During the isothermal expansion portion of this engine's cycle, the volume of the gas doubles. This means V2 = 2*V1 (and V4 = 2*V3)

Step 2:For a carnot engine:

V2/V1 = V4/V3

Work = nR((T1)ln(V2/V1) - (T2)ln(V4/V3))

⇒with Work = the work done in the cycle = 940J

⇒with n = the number of moles = 1.50 moles

⇒with R = the gas constant = 8.314 J/mol*K

⇒with T1 = the hot temperature

⇒With T2⇒ the cold temperature

where R = 8.31 J/mol K Gas Constant

940J = 1.5moles * 8.314 J/mol*K * (T1*ln(2) - T2*ln(2)))

940 = 1.5 * 8.314 ln(2) * (T1-T2)

(T1-T2) = 940 / (1.5*8.314*ln(2))

(T1-T2) = 108.7K

For the reversible adiabatic expansion: T2 = T1*(V1/V2)^(R/Cv). Where V2/V1 = 5.7 (Because during the adiabatic expansion the volume increases by a factor of 5.7)

For a monatomic ideal gas, Cv = 3/2R

When we combine both, we'll have:

T2 = T1*(1/5.7)^(R/3/2R)

T2 = T1*(1/5.7)^(2/3)

T2= T1 * 0.31

Since we know that (T1-T2) = 108.7K

we have:

T1 - 0.31T1= 108.7K

0.69T1 = 108.7K

T1 = 157.5K

T2 = 157.5*0.31 = 48.8K

You work in the special effects department of a movie studio. You are currently working on a superhero movie where the hero is very
strong and cannot be hurt by normal weapons such as a sword. In the next scene, the villain
is going to hit the hero with a lead pipe.
The hero's costume is mostly made of foam and carbon so that is it very light and easy to move around in but will crumble if hit with
anything hard. For this scene, a section of the
costume needs to be replaced with a different material that will only dent, not crumble,
when hit with the pipe. You are on a deadline and look around the props
department for ideas, what could you use?
A. You find sheets of copper (Cu) used in an induced rescue factory scene
B. You find a barrel of phosphorus (P) used as a component in explosive powder
C. You find a tank of helium (He) used for balloons
D. You find large desk of Chlorine (Cl) used to kill bacteria and pools

Answers

Answer:

A. You find sheets of copper (Cu) used in an induced rescue factory scene

Explanation:

I would use a sheets of copper (Cu) used in an induced rescue factory scene because, copper is a metal and the only material out of the other options that would only dent and not crumble when hit by the lead pipe.

The other options in B - D are non-metals.

Phosphorus is a non-metal and is used as an explosive and thus cannot be used.

Helium is a gas used in filling balloons and thus cannot be used.

Chlorine is used in killing bacteria and thus cannot be used.

So, copper is the only option available since it is a metal and can thus accommodate a large force.

So, option A is the answer.

Part C – RC Circuits in AC Mode 1. Derive Equation 5-6 from Equation 5-5. 2. Using the τ’s you calculated and your measured resistance: a. Calculate the capacitances of the capacitors. b. Compare your calculated and measured values via percent error.

Answers

Answer: hi your question is incomplete attached below is the complete question

1) attached below

2) a)  31 Ω,   302.9 Ω

   b)  17.3 Ω ,  26.4 Ω

Explanation:

1) Deriving Eqn 5-6 from Eqn 5-5

attached below

2) using τ’s calculated and measured resistance

use given data

Tm1 = Rm1 * Cm1

       = 329.3 * 333 * 10^-9 = 109.65 μs

Tm2 = Rm2 * Cm2

       = 329.3 * 200 * 10^-9 = 658.6 μs

a) Capacitance of capacitors

For Cm1

   t₁₂ = 72 μs = R₁' Cm1 log²

 ∴ R₁' = ( 72 * 10^-6 ) / ( 333 * 10^-9 log² )

         = 31 Ω

For Cm2

 t₁₂ = 40 μs  , ∴  R₂' = 302.9 Ω

b) comparing calculated and measured values via percent error

errors

Rm1 - R₁' = 17.3 Ω

Rm2 - R₂' = 26.4 Ω

2. Below what depth would a submarine have to submerge so that it would not be swayed by surface waves with a wavelength of 24 meters?

Answers

Answer: Below 12m of depth, the submarine has to submerge so that it would not be swayed by surface waves

Explanation:

To avoid the surface waves, a submarine has to submerge below the wave base. It is the position below which the motion of the waves is negligible.

This wave base is equal to half of the wavelength. The equation becomes:

Wave base = [tex]\frac{\text{Wavelength}}{2}[/tex]

We are given:

Wavelength = 24 m

Putting values in above equation, we get:

Wave base = [tex]\frac{24m}{2}=12m[/tex]

Hence, below 12m of depth, the submarine has to submerge so that it would not be swayed by surface waves

Steel wire rope is used to lift a heavy object. We use a 3.1m steel wire that
is 6.0mm in diameter and lift a 1700kg object. Then, the wire elongates
0.17m. Calculate the Young’s modulus for the rope material.

Answers

Answer:

Young's modulus for the rope material is 20.8 MPa.    

 

Explanation:

The Young's modulus is given by:

[tex] E = \frac{FL_{0}}{A\Delta L} [/tex]

Where:

F: is the force applied on the wire

L₀: is the initial length of the wire = 3.1 m

A: is the cross-section area of the wire

ΔL: is the change in the length = 0.17 m

The cross-section area of the wire is given by the area of a circle:

[tex] A = \pi r^{2} = \pi (\frac{0.006 m}{2})^{2} = 2.83 \cdot 10^{-5} m^{2} [/tex]

Now we need to find the force applied on the wire. Since the wire is lifting an object, the force is equal to the tension of the wire as follows:

[tex] F = T_{w} = W_{o} [/tex]

Where:

[tex] T_{w} [/tex]: is the tension of the wire

[tex]W_{o} [/tex]: is the weigh of the object = mg

m: is the mass of the object = 1700 kg

g: is the acceleration due to gravity = 9.81 m/s²

[tex] F = mg = 1700 kg*9.81 m/s^{2} = 16677 N [/tex]

Hence, the Young's modulus is:

[tex] E = \frac{16677 N*0.006 m}{2.83 \cdot 10^{-5} m^{2}*0.17 m} = 20.8 MPa [/tex]          

Therefore, Young's modulus for the rope material is 20.8 MPa.                

I hope it helps you!                                    

trình bày nguyên lý Đa lăm be

Answers

I don’t understand this question

Which image illustrates reflection?
A
B
с
D

Answers

Answer: I beleive A

Explanation:

Answer:

A

Explanation:

We can see the light being reflected off the mirror.

Which is the most difficult subject?​

Answers

Answer:

Quantum Mechanics

Explanation:

Well, that's what I think personally.

Container A and container B hold samples of the same ideal gas. The volume and the pressure of container A is equal to the volume and pressure of container B, respectively. If Container A has half as many molecules of the ideal gas in it as Container B does, then which of the following mathematical statements is correct regarding the absolute temperatures TA and TB in Container A and Container B. respectively?
A. TA = TB/2.
B. TA = 4TB.
C. TA = TB/4.
D. TA = 2TB.
E. TA = TB

Answers

Answer:

A. TA = TB/2.

Explanation:

Since container A has half as many molecules of the ideal gas in it as container B. Therefore, container A will have half the volume of gas as in container B:

[tex]V_A = \frac{1}{2}V_B[/tex]

Now, from Charle's Law:

[tex]\frac{V_A}{T_A}=\frac{V_B}{T_B}\\\\\frac{1}{2}\frac{V_B}{T_A}=\frac{V_B}{T_B}\\\\T_A = \frac{T_B}{2}[/tex]

Hence, the correct option is:

A. TA = TB/2.

b) Assume the rod is 0.60 m long and has a mass of 0.50 kg, and the clay blob has a mass of 0.20 kg and moves at an initial velocity of 8.0 m/s. Calculate the final angular velocity of the rod. Be sure to put units in your calculation and show the resulting units in your answer.

Answers

Answer:

The correct answer is "6.96 rad/s".

Explanation:

The given values are:

Length,

L = 0.6 m

Mass,

m₁ = 0.5 kg

m₂ = 0.2 kg

Initial velocity,

V = 8 m/s

Now,

The final angular velocity will be:

⇒ [tex]\omega =\frac{6m_1V}{(4m_1+3m_2)L}[/tex]

By substituting the values, we get

⇒     [tex]=\frac{6\times 0.2\times 8}{(4\times 0.2+3\times 0.5)0.6}[/tex]

⇒     [tex]=\frac{9.6}{1.38}[/tex]

⇒     [tex]=6.96 \ rad/s[/tex]

Soap bubble coloring example:
(reflection, interference, refraction, diffraction)​

Answers

Explanation:

Interference is the example of soap bubble colouring

EXTRA INFO:

(LOOK AT THE IMAGE)

An incoming light ray is partly reflected by the top surface of the soap film and partly reflected by the bottom surface. The wave reflected from the bottom surface has traveled further (an extra distance equal to twice the thickness of the film) so emerges out of step with the top wave. When the two waves meet, they add together, and some colors are removed by destructive interference. Where the film is thickest, the bubble appears more blueish; where it's thinner, it will look more violet or magenta.

[tex]\huge\bold\color{black}{ANSWER}[/tex]

Soap bubble coloring example: INTERFERENCE

IS ANYONE THERE..??!​

Answers

Answer:

hmmmmmmmmmmmmmmmmmmmmmmmm y

A flat coil of wire is placed in a uniform magnetic field that is in the y-direction.
The magnetic flux through the coil is maximum if the coil is:_________.
(a) in the XY plane
(b) in either the XY or the YZ plane
(c) in the XZ plane
(d) in any orientation, because it is constant.

Answers

Answer:

The correct answer is c

Explanation:

Flow is defined by

        Ф =  B . A

bold letters indicate vectors.

The magnetic field is directed to the y axis, The area of ​​the coil is represented by a vector normal to the plane of the coil, so to have a flux

                i.i = j.j = k.k = 1

and the tori scalar products are zero

a) If the coil must be in the xy plane so that its normal vector is in the Z axis, so there is no flux

b) if the coil is in the plane yz the normal veto is in the x axis, so the flux is zero

C) If the coil is in XZ, the normal vector points in the y direction, usually the scalar product is one and there is a flux in this configuration

The correct answer is c

This diagram shows the magnetic field lines near the ends of two magnets. There is an error in the diagram.

Two bar magnet with the north pole of one near the south pole of the second. field lines are leaving the north pole and bent away from the south pole of the other. Field lines are leaving the south pole of one and bending away from the north pole of the other.
Which change will correct the error in the diagram?

a)changing the N to S
b)reversing the arrows on the left to point toward the N
c)changing the S to N
d)reversing the arrows on the right to point toward the S

Answers

Answer:

changing the N to S. that's how the error will be corrected

Answer:

C is the correct answer

Explanation:

i took the test

An audience of 2250 fills a concert hall of volume 32000 m^3. If there were no ventilation, by how much would the temperature of the air rise over a period of 2.0 h due to the metabolism of the people (70 W/person)?

Answers

246 and 64 minutes later

why is it wrong to leave our light on​

Answers

Answer:

you will get huge electricity bills ............

Differentiate between Scalar quantity and Vector quantity and give two examples each​

Answers

Answer:

A scalar quantity is a physical quantity which only has magnitude. Scalars can be added algebraically.A vector quantity is a physical quantity which has both magnitude and direction. Vectors should be added vectorially.

Help pleaseeeeeeeeeeeeee

Answers

Answer:

hello the answer is 47m/s

A TV satellite dish is designed to receive radio waves of wavelength
0.0644 meters. What is the frequency of the waves it receives? _______GHz

Give your answer in gigahertz (GHz). 1 GHz = 10^9 Hz.

Give your answer to the nearest tenth of a GHz (one place after the decimal). Just enter the number; do NOT use scientific notation.

Answers

Answer:

4.7 GHz

Explanation:

Applying,

v = λf................. Equation 1

Where v = velocity of the radio wave, λ = wavelength, f = frequency

make f the subject of the equation

f = v/λ.............. Equation 2

Note: A radio wave is an electromagnetic wave, as such it moves with a velocity of 3.00 x 10⁸ m/s

From the question,

Given: λ = 0.0644 meters

Constant: v = 3.00 x 10⁸ m/s

Substitute these values into equation 2

f = (3.00 x 10⁸)/0.0644

f = 4.66×10⁹ Hz

f = 4.7 GHz

which has higher eneergy electron r proton

Answers

Answer:

proton have higher energy than electron

Explanation:

tag me brainliest

Answer:

proton

Explanation:

proton is higher energy than the electron

The diagram here shows an image being formed by a convex lens. Compared to the object at right, the image at left is-

larger and upright.

smaller and upright.

smaller and upside down.

larger and upside down.

Answers

Answer:

Smaller and upside down

Explanation:

To answer the question, we must recognise that the characteristics of the image formed by a convex lens depends on the position of the object from the lens.

From the diagram given in the question above, the following data were obtained:

1. The image is smaller than the object.

2. The image is inverted i.e upside down.

3. The image is closer to the lens

4. The image between 2f and f

Now, considering the options given in question above, the correct answer to the question is:

The image is smaller and upside down.

A ​12.5-m fire truck ladder is leaning against a wall. Find the distance d the ladder goes up the wall​ (above the fire​ truck) if the ladder makes an angle of with the horizontal

Answers

Complete Question

A 12.5-m fire truck ladder is leaning against a wall. Find the distance d the ladder goes up the wall​ (above the fire​ truck) if the ladder makes an angle of  

40° 16' with the horizontal.

Answer:

 [tex]d=8.01m[/tex]

Explanation:

From the question we are told that:

Length of ladder [tex]l=12.5m[/tex]

Angle [tex]\theta=40° 16'=20.26 \textdegree[/tex]

Generally the Trigonometric equation for distance d it goes up the wall is mathematically given by

 [tex]d=l sin \theta[/tex]

 [tex]d=12.5 sin 40.26[/tex]

 [tex]d=8.01m[/tex]

Hi can someon help me how to answer this?
Btw I'm from Philippines

Answers

Answer:

Test 1

1.True

2.True

3.True

4.False

5.True

6.True

7.False

8.True

9.True

10.True

yung iba nasa pic

You are stranded in a stationary boat. Your friend is on a dock, but the boat is just beyond his reach. There is a 5 kg anchor in the boat. You'd like to get the boat to move closer to the dock so your friend can rescue you. Select from the following list what effect each change will have on the position of the boat relative to the dock. A. The boat will move closer to the dock. B. The boat will move away from the dock. C. The position of the boat relative to the dock will not change.

Answers

Answer:

running away and launching the anchor that will give a greater speed towards the dock v₄.

Explanation:

To try to bring the boat closer to the dock, several cases can be carried out.

* move inside the ship so that the center of mass changes and since moving away you have a speed v, the ship will approach the dock at a speed v₂,

* Throw the anchor in the opposite direction to the dock so that using the conservation of the moment the boat moves towards it, it moves at a speed v₃

* A combination of the two processes running away and launching the anchor that will give a greater speed towards the dock v₄.

In all cases, the friction must be zero.

All other movements move the ship away from the dock

At which point is the kinetic energy of the pendulum the greatest?

C

A

D

B

Answers

Answer:

Point C

Explanation:

Greatest Kinetic Energy means lowest potential energy since energy is conserved. Lowest potential energy means lowest height which is at Point C.

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