lana summarized what happens when a ball sitting on top of a grassy hill rolls down the hill.

The motionless ball has potential energy. Once the ball starts to roll down the hill, new kinetic energy is made. As the ball rolls across the grass, it slows down. The kinetic energy of the ball is converted to other forms of energy.

Which best describes Alana’s error?

The motionless ball does not have energy because it is still.
Kinetic energy is not made; it is a result of energy transformation.
The ball cannot slow down unless someone touches it.
The energy is not converted; it disappears.

Answers

Answer 1

Answer:

Kinetic energy is not made; it is a result of energy transformation

Explanation:

Let's discuss what happens to the ball when it is on top of the mountain and rolls down.

Initially the ball has a total mechanical energy, which at this point is potential.

         Em₀ = U = mg h

When the ball starts to roll down, part of this potential energy will be transformed into kinetic energy.

        Em = K + U = ½ m v² + mg y

but mechanical energy is conserved.

The presence of the grass introduces a force in the opposite direction that creates a friction force work (not conservative), for which the total mechanical energy decreases

          W_{friction}= Emf - Emo  

When examining the answers, the one that best describes Lana's error is:

Kinetic energy is not made; it is a result of energy transformation

Answer 2

Answer:

Your answer is B) Kinetic energy is not made; it is a result of energy transformation.

Explanation:


Related Questions

What charge does an object have if it has an excess of electrons?

Answers

Answer:

negative charge

Explanation:

On an atomic scale, those are called "ions", and negatively charged ions are called anions.

An object with a mass of 1.5 kg accelerates 10.0 m/s^2? when an unknown force is applied to it. What is the amount of the force?

Answers

Answer:

15 N

Explanation:

f=ma

f=1.5*10

f=15 N

The _____is a measure of the number of waves that pass a point in a given amount of time

Answers

The answer is frequency
Answer: wave frequency

I would assume its A. or B.

Answers

Answer:

B

Explanation:

remember that you are looking for the value of the graph

to take into account or value a lot: prize, estimate to value your opinion. 2nd: estimate or assign the monetary value of: appraise a necklace. b: qualify or scale in utility, importance or general value: evaluate. value.

When the net force acts at right angles to an object’s motion, what does it do to the object’s motion?
a. it changes the object’s speed
b. it changes the object’s direction
c. it changes both the speed and direction of the object’s motion.

Answers

Answer:

B. It changes the objects direction

1. A 110.0 g sample of metal is warmed 10.0 °C when 70.0 calories is added. What is the specific heat of this metal?

2. How much heat must be supplied to a 550.0 g aluminum pan to raise the temperature of the pan from 14.0°C to 108.0 °C?

Answers

Answer:

1. The specific heat of the meatal is approximately 0.266 J/(g·°C)

2. 46.6334 kJ

Explanation:

1. The given mass of the sample of metal, m = 110.0 g

The temperature change of the metal when heat is added, ΔT = 10.0°C

The amount of head that was added, ΔH = 70.0 Calories = 292.88 Joules

The formula for heat heat capacity of a material is given as follows

Q = m × c × ΔT

Where;

Q = The quantity of heat added = 292.88 Joules

m = The mass of the material = 110.0 g

ΔT =  The temperature change = 10.0°C

c = The specific heat capacity of the material

We get;

c = ΔH/(m × ΔT)

Which gives;

c = 292.88 J/(110.0 g × 10.0°C) ≈ 0.266 J/(g·°C)

2. The given mass of aluminum, m = 550.0 g

The initial temperature of the aluminum, T₁ = 14.0°C

The final temperature of the aluminum, T₂ = 108.0°C

The specific heat of aluminum, c = 0.902 J/(g·°C)

We get;

Q = m × c × (T₂ - T₁)

Q = 550.0 g × 0.902 J/(g·°C) × (108.0°C - 14.0°C) = 46,633.4 joules = 46.6334 kJ

The heat that must be supplied to 550.0 g of aluminum pan to raise the temperature of the pan from 14.0°C to 108.0°C, Q = 46.6334 kJ.

if you have any questions, let me know​

Answers

Answer:

The red car would experience the greatest acceleration.

Explanation:

Newton says that Force equals mass times acceleration or F = ma

We get a = F/m

If we want the greatest acceleration or a, mass or m must be the lowest.

a microwave with a frequency of 5.0 x 10^10 hertz has a period of

Answers

Answer:

A microwave with a frequency of 5*10¹⁰ hertz has a period of 2*10⁻¹¹ seconds.

Explanation:

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

The period is the time that elapses between the emission of two consecutive waves. In other words, it is the time it takes for a complete wave to pass a reference point. The period (T) is simply the inverse of the frequency (f):

[tex]T=\frac{1}{f}[/tex]

In this case, f=5*10¹⁰ Hz. So, replacing in the definition of period T:

[tex]T=\frac{1}{5*10^{10} Hz }[/tex]

Solving:

T= 2*10⁻¹¹ seconds

A microwave with a frequency of 5*10¹⁰ hertz has a period of 2*10⁻¹¹ seconds.

A microwave with a frequency of 5*10¹⁰ hertz has a period of 2*10⁻¹¹ seconds.

What is fequency?

The fequency is defined as the number of cycles achieved by the any wave it is expressed in hertz.

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

The period is the time that elapses between the emission of two consecutive waves. In other words, it is the time it takes for a complete wave to pass a reference point. The period (T) is simply the inverse of the frequency (f):

[tex]T=\dfrac{1}{f}[/tex]

In this case, f=5*10¹⁰ Hz. So, replacing in the definition of period T:

[tex]T=\dfrac{1}{5\times 10^{10}}=2\times 10^{-11}\ Sec[/tex]

A microwave with a frequency of 5*10¹⁰ hertz has a period of 2*10⁻¹¹ seconds.

Thus a microwave with a frequency of 5*10¹⁰ hertz has a period of 2*10⁻¹¹ seconds.

To know more about Frequency follow

https://brainly.com/question/25699025

what is a material used to reduce or prevent the transfer of electricity, heat, or sound ?

Answers

Answer:

The material you're looking for is insulation.

Explanation:

It reduces and/or stops electricity waves, heat waves, and sound waves from going past.

A nucleus splits to form two or more smaller nuclei during which process?
A. Positron emission
B. Nuclear fission
C. Nuclear fusion
O D. Gamma decay

Answers

Answer:

nuclear fission

The distance covered by a car moving with a speed of 36 km/h in 20 minutes is

Answers

Answer:

D=12000m

Explanation:

Distance

Speed=distance/time

Where, speed is given in m/s

Time is given in s

Distance is given in m

Data

S=36km/h

T=20minutes

D=?

D=S*T

D=(36*1000m)/3600s*(20*60s)

D=36000m/3600s*1200s

D=10m/s*1200s

D=12000m

Determine the mass of fuel required for the expected energy consumption in the United States for the next 10 years:

Provide the energy use per person per year in the United States = 3.5 × 1011 joules.
Base your calculations on a current population of 310,000,000.

Answers

Answer:

(This will depend on the type of fuel, I will assume that the fuel is petrol)

First, let's find the expected energy consumption in the US for the next 10 years.

We know that in one year, a person consumes 3.5*10^11 joules.

There are 310,000,00 people on the US

Then the total consumption in one year is:

310,000,000*3.5*10^11 joules = 1.085*10^20 J

In 10 years the consumption is 10 times the consumption of a single year, then the expected energy consumption in the US for the next 10 years is:

10*1.085*10^20 J = 1.085*10^21 J

Now let's find the mass of fuel required.

We know that a liter of petrol has 31,536,000 joules of energy,

And a liter of petrol weights 0.75 kg

To find the number of liters of petrol that we need, we need to find the quotient between the expected energy consumption in the next 10 years and the energy of a single liter of petrol, this is:

N = (1.085*10^20 J)/(31,536,000 j) = 3.44*10^13

We will need  3.44*10^13 liters of petrol.

And the total mass of petrol will be:

M = 3.44*10^13*0.75 kg = 2.58*10^13 kg of fuel.

over due by alot please help

Answers

Answer:

i would say the third one

Explanation:

may i be brainliest?

A car moving with a speed of 20 m/s
applies brakes. What is the acceleration
of the car?​

Answers

Explanation:

[tex]speed : U = 20 \: m {s}^{ - 1} \\ {V}^{2} = {U}^{2} + 2aS \\ 0 = {20}^{2} + (2 \times a \times S) \\ a = \frac{200}{S} \: m {s}^{ - 1} [/tex]

Which of the following describes the moon’s motion around Earth?
A) The moon is in free fall around the Earth.
B)The acceleration of the moon is toward the center of Earth.
C)The moon is falling toward the center of Earth and away from the straight line path it would travel without gravity.
D)All are correct.

Answers

Answer:

i think B?

Explanation:

1.) A ball is thrown horizontally from the top of a building. What is the vertical velocity of the ball after 1 second?

A. 0 m/s
B. 9.8 m/s
C. 4.9 m/s
D. 19.6 m/s

2.) This is a required question
What is the horizontal acceleration of a projectile?

A. 0 m/s2
B. 8.9 m/s2
C. 4.9 m/s2
D. 9.8 m/s2

3.) If air resistance is neglected, at what angle a projectile must be projected to attain the maximum range?

A. 40
B. 75
C. 45
D. 90

4.) Neglecting air resistance, the range of a projectile projected at an angle of 20 degrees is the same as that of _______ if they were released with the same velocity.

A. 50
B. 70
C. 60
D. 80

5.) What do you call the motion of an object with constant acceleration?

A. circular motion
B. uniform motion
C. constant motion
D. uniformly accelerated motion


CAN SOMEONE PLEASE HELP ASAP. THANK U

Answers

9.8zero 4570Uniform accelerated motion

Explanation:

Q.1 - V = u + at

u = 0, a = g = 9.8, t = 1

V = 0+9.8*1 = 9.8 m/s

Q 2- In horizontal position the velocity remains same hence a= dv/t, since change in velocity is zero the acceleration also equal to zero

Q.3- After neglecting the air resistance at 45° angle the maximum range is obtained.

let's prove, consider the range have maximum angle at θ, now range is given by

R = u²Sin2θ/g where sin2θ can we written as 2sinθ.cosθ.

Now the range value is directly proportional to the product of sin & cos of firing angle & this maximum value is obtained at 45°

Q.4 The range of two angle will be same if and only if they give 90° on addition.

20+x = 90,

x = 90-20 = 70°

Q.5 The motion with constant acceleration is known as uniformly accelerated motion.

Thanks for joining brainly community!

Answer:

B. 9.8 m/sA. 0 m/C. 45°B. 70°D. uniformly accelerated motion

Explanation:

1.

u=0m/s

v=?

a=9.8m/s²

t=1sec

now

we have

v=u+at

v=0+9.8*1

v=9.8m/s

3.

angle is measured in sin and cos angle where maximum angle's value is gained by 45°

4.

we have

range

R=[tex]\frac{u²sin2\theta}{g}[/tex]

For

angle =20°

R1=[tex]\frac{u²sin2*20}{g}[/tex].......[1]

another angle be [tex]\theta[/tex]

R2=[tex]\frac{u²sin2\theta}{g}[/tex].......[2]

since R1=R2

By comparing we get

Sin40=Sin([tex]2\theta[/tex])

Sin(180-40)=Sin([tex]2\theta[/tex])

we

140=[tex]2\theta[/tex]

[tex]\theta[/tex]=70°

Unbalanced forces cause a change in motion.

How do you know this?

Answers

Answer:

This happens in two ways. If an object is at rest and an unbalanced force pushes or pulls the object, it will move. Unbalanced forces can also change the speed or direction of an object that is already in motion.

Explanation:

Question 7 of 10
What is kinetic friction?
A. Friction that acts when an object is not moving
B. Friction that opposes air resistance
C. Friction that exerts no force
D. Friction that acts on a sliding object
SUBMIT

Answers

Kinetic friction (also referred to as dynamic friction) is the force that resists the relative movement of the surfaces once they're in motion.
https://www.khanacademy.org › stat...
Static and kinetic friction example (video) | Khan Academy

Answer a would be static friction
Answer b is fluid friction
(Air resistance is fluid friction. Fluid friction is the friction experienced by objects which are moving in a fluid and the air is a fluid.)
Answer c is static friction
ANSWER D IS KINETIC FRICTION

Hope this helps :D



Answer: Friction that acts on a sliding object

Explanation:

A bicycle with a mass of 100kg hit a wall at an acceleration of 4 m/s2, what is the force?

Answers

Answer:

400N

Explanation:

F= ma

F= 100 x 4

F= 400N

help please, it’s on my physics paper!

Answers

Answer:

15.4

Explanation:

770x14% = 107.8

rearrange f =kx to get k (constant)

k = f/x

x is the distance stretched , so 42 - 35 =7

so 107.8/7 =15.4

can someone double check

Answer:

k = 44000 N/m is the answer.

Explanation:

Gravitational Potential Energy = 770J

Elastic Potential Energy = 14% of 770J

= 14/100 × 770

= 107.8J

Extension (x) = 42 - 35 = 7cm = 7 × 10⁻²m

To find the spring constant (k)

Elastic Potential Energy Formula:

[tex]U = \frac{1}{2}kx^2[/tex]

107.8 = 1/2 × k × (7 × 10⁻²)²

215.6 = 0.0049 × k

k = 215.6/0.0049

k = 44000 N/m

Can some one help me with this question its hard :( down below ill give brainliest

Answers

I’m pretty sure it’s c sorry if I’m wrong

According to the law of conservation of momentum, in a(n) _______ system, the initial total momentum before a collision equals the final total momentum.​

Answers

Answer:

rhastuutse5r says he n and happiness of

Explanation:

UKDIAMOND is a great place to live and live and live in the world best friend tum jio hjaro and happiness of the day and the day of the day of the day of the day of the day of the day of 2nd century and the day of the day of

Answer:

Isolated

Explanation:

According to the law of conservation of momentum, in a(n) isolated system, the initial total momentum before a collision equals the final total momentum. I just did it on A p e x.

If a running system has a total change in the heat of 315 joules, and it is running at a temperature of 350 K, what is the entropy? Α.1.54 joules/kelvin B.0.847 joules/kelvin C.1.22 joules/kelvin D. 0.900 joules/kelvin E. 0.762 joules/kelvin​

Answers

Answer:

0.900

Explanation:

joules" (and any subsequent words) was ignored because we limit queries to 32 words.

Answer:

See image

Explanation:

Plato

Can someone write a 200 speech that explains the difference between analog and digital waves and which one is better?

Answers

Answer:

Analog and digital signals are the types of signals carrying information. The major difference between both signals is that the analog signals have continuous electrical signals, while digital signals have non-continuous electrical signals.

Explanation:

Analog Signals   were used in many systems to produce signals to carry information.  These signals are continuous in both values and time. The use of analog signals has been declined with the arrival of digital signals. In short, to understand the analog signals –  all signals that are natural or come naturally are analog signals.  Digital Signals , unlike analog signals, digital signals are not continuous, but signals are discrete in value and time. These signals are represented by binary numbers and consist of different voltage values.  Their differences are as follows:

Analog Signals                                      Digital Signals

Continuous signals                               Discrete signals

Represented by sine waves               Represented by square waves

The Human voice, natural sound, analog electronic devices are few examples   Computers, optical drives, and other electronic devices

A Continuous range of values            Discontinuous values

Records sound waves as they are     Converts into a binary waveform.

Only be used in analog devices.        Suited for digital electronics like computers, mobiles, and more.

I think a Digital signal is better.

transparent materials allow electromagnetic waves to be while trapping thermal energy

1. transmitted
2. reflected
3. absorbed

Answers

Answer:

2. reflected

hope it is helpful to you

What process is represented by this redox equation ? 6H 2 O+6CO 2 C 6 H 12 O 6 +6O 2

Answers

Answer:

C. Photosynthesis

Explanation:

Photosynthesis is a process by which plants and photosynthetic bacteria obtain their food in presence of sunlight from water and carbon dioxide. They produce glucose as the food and oxygen is emitted as the byproduct. The equation for photosynthesis is - 6H2O+6CO2 → C6H12O6 + 6O2

Thus, the correct answer is 'C.Photosynthesis.'

What is the speed of a wave with a frequency of 6 Hz and a wavelength of 12 m? No links

Answers

72 m/s

Explanation:

Given,

Frequency ( f ) = 6 Hz

Wavelength ( λ ) = 12 m

To find : -

Speed ( v ) = ?

Formula : -

v = f x λ

v

= 6 x 12

= 72 m/s

Therefore,

the speed of a wave with a frequency of 6 Hz and a wavelength of 12 m is 72 m/s.

Chang wants to build a circuit that will light up the bulb from a flashlight. Which component could Chang leave out and still light up the bulb? the switch the battery the wire the light bulb

Answers

We could choose to leave out the switch and simply join the wires together and the bulb will still light up.

What is a circuit?

A circuit is defined as pathway that has been designed for the flow of current. Now we know that a circuit must have a battery, connecting wires and the bulb itself.

However, we could choose to leave out the switch and simply join the wires together and the bulb will still light up.

Learn more about circuit: https://brainly.com/question/365923

Use the image above to answer the following for 2 points each:

1. Identify a point in the diagram where a divergent boundary is occurring and explain how it is interacting with the rock cycle.

2. Identify a point in the diagram where a divergent boundary is occurring and explain how it is interacting with the rock cycle.

3. Identify a point in the diagram where the rock cycle is occurring without a plate boundary and how it is interacting with the rock cycle.

Answers

Answer: the divergent one goes where it looks like there a crack because when you think about divergent it means dividing like seperating.(igneous rock) is where the divegent one goes.

the one that is no plate boundary is sedimentary rock and it occurs by because there is nothing there for it todo there

Explanation:

What information is represented by the slope of a graph of displacement versus time (displacement-time graph)?​

Answers

C - velocity

When you look at a point it is saying it goes this many meters in this amount of time. This is speed which means the slope is velocity
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