A particle moves along the x-axis so that at any time t≥0 its position is given by x(t) = t3 − 3t2 − 9t. For what values of t is the particle at rest?

Answer:

Explanation:

Yes she is doing work. With or without the groceries, she is still doing work. She does more work with the groceries than without because Work is defined by F which is defined by mass. The mass increases with the groceries.

The work done is against the force of gravity.

Answer:

it is b on edge not d, well atleast for me it was b

Explanation:

Answer:

B) one battery, two switches, and three light bulbs

Explanation:

Answer: It would be the dependent variable.

Explanation:

The dependent variable is limited and can be affected by the changes and manipulation of the independent variable.

Answer:

[tex]Q_t= 8.3 * 10^3 C[/tex]

Explanation:

From the question we are told that:

Resistor [tex]R=1000ohms[/tex]

Voltage [tex]v=120_V[/tex]

Capacitance of c_1 [tex]c_1=20 \mu F[/tex]

Capacitance of c_2 [tex]c_2=60 \mu F[/tex]

Time [tex]t=0[/tex]

Generally the equation for charges is mathematically given by

[tex]For C_1\\Charge\ on\ C_1 = CV = 20*120 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2.4 x 10^-3 C\\[/tex]

[tex]ForC_2\\Charge on C_2 = 60*120 =7200 μC = 7.2 x 10^-3\\Charge on C_2 = 7.2 x 10^-3[/tex]

Generally the equation for voltage across capacitors is mathematically given by

[tex]V_c(t)=V(1-e^{-t/RC})[/tex]

[tex]C=C_1+C_2=80 \mu f\\t=2RC=>160000s[/tex]

[tex]V_c(t)=120(1-e^{-(160000)/1000*(80)})[/tex]

[tex]V_c(t)=103.7598[/tex]

Generally the equation for charges is mathematically given by

[tex]Q1(t) = C1Vc(t)\\Q1(t) = 20*103.7598\\Q1(t) = 2075.196\\\\Q2(t) = 60*103.7598\\Q2(t) = 6225.6\\[/tex]

Generally the equation for total charges [tex]Q_t[/tex] is mathematically given by

[tex]Q_t=Q1(t)+Q2(t)[/tex]

[tex]Q_t= 8.3 * 10^3 C[/tex]

Answer:

125

Explanation:

use the formula e=1/2mv² and use m=10 and v=5

this produces the equation e=1/2x10x25=125

dont forget the units (J) ;)

Answer:

125J

Explanation:

K.e=1/2mv^2

=1/2(10)(5)^2

=125J

Answer:

A

Explanation:

The answer is A because proton number is the same as atomic number

Answer:

The right solution is "2.5 m/s²". A further explanation is given below.

Explanation:

The given values are:

Initial velocity,

= 20 m/s

Final velocity,

= 0 m/s

Time,

= 8 s

As we know,

⇒  [tex]Acceleration=\frac{Final \ velocity-Initial \ velocity}{2}[/tex]

On substituting the values, we get

⇒                       [tex]=\frac{0-20}{8}[/tex]

⇒                       [tex]=\frac{-20}{8}[/tex]

⇒                       [tex]=-2.5 \ m/s^2[/tex]

Answer:

increasing

Explanation:

Given that,

Initial angular speed =1 rad/s

Angular acceleration = 0.5 rad/s²

We know that the angular acceleration is given by :

[tex]\alpha =\dfrac{\omega_f-\omega_i}{t}[/tex]

Where

[tex]\omega_f[/tex]city and t is time is the final angualr velo

As the angular acceleration of the object is positive. It means that the final speed of the object is more than that initial. As a result, the speed of its rotation is increasing.

Answer:

Explanation:

A wave is a phenomenon that travels through a material medium without any permanent effect on the medium. It can be classified as mechanical or electromagnetic waves. And the two major types are transverse and longitudinal.

From the given question;

1. Longitudinal waves e.g sound waves, waves in a spring'

2. Frequency (number of cycles per second).

3. Wavelength of the wave. Measured in meters.

4. Transverse waves e.g light waves, water waves.

5. Wave speed.

6. Electromagnetic waves e.g ultraviolet waves, X-rays etc.

7. Amplitude.

8. Hertz.

9. Rarefaction

10. Compression

A wave is a phenomena that flows across a material medium without leaving any lasting mark.

1.Wave motion that is parallel to the wave direction is described

as longitudinal wave.

A wave is a phenomena that flows across a material medium without leaving any lasting mark. Mechanical or electromagnetic waves can be used to classify it. Transverse and longitudinal are the two main forms.

1.Wave motion that is parallel to the wave direction is described

as longitudinal wave.

2.Frequency is defined as the number of cycles per second.. The time to make one complete cycle is frequency.

3.Wavelength of the wave is measured in meters.The distance between successive crests of a wave is wavelength.

4. Examples of Transverse waves are light waves, water waves.. Wave motion that is perpendicular to wave direction describes transverse wave.

5.The number of waves that passes a given point in time is Wave speed.

6.Examples of Electromagnetic waves are ultraviolet waves, X-rays etc.

Electroimegnetic wave is a kind of wave that does not need a medium.

7.The highest point of a wave is called amplitude.

8.The unit for frequency is Hertz.

9. A region in a medium of longitudinal wave where molecules are Rarefaction.

10.  A region in a medium of longitudinal wave where molecules are

packed is called compression.

To learn more about the wave refer to the link;

https://brainly.com/question/3004869

Answer:

a = 2 m/s²

Explanation:

Given: 20 g, 40N

To find: Acceleration (a)      

Solution: To find the acceleration (A), divide the force by the weight    

A = F ÷ m

=  40 ÷  20

= 2 m/s²

Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.

Answer:

Explanation:

Newton's first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This postulate is known as the law of inertia.

hope this helps :))

There is no force acting on the baseball the statement best explains why the baseball remains motionless.

A body wants to remain in its original position until or unless the external force is not applied to it. Such a phenomenon is known as inertia.

Newton's first law asserts that if a body is at rest or traveling at a uniform speed in a straight direction,

It will remain at rest or continue to move in a straight path at a constant speed until acted on by a force. This is referred to as the law of inertia.

There is no force acting on the baseball the statement best explains why the baseball remains motionless.

Hence option B is correct.

To learn more about the inertia refer to the link;

https://brainly.com/question/3268780

Answer:

When the sum of all forces applied to the object is 0.

Explanation:

N2L states that net force equals an object's mass times its acceleration (F = ma). If the net force is 0, the acceleration of the object is 0.

On the second note, when an object has 0 acceleration (which means it has a constant velocity), it is in equilibrium (N1L).

Answer:96 W

Explanation:

The eccentricity is 0.5

Answer:

The correct option is (d).

Explanation:

Hence, the correct option is (d).

The thermal energy is related to the kinetic energy of atoms, ions, and molecules.

The thermal energy of any material is defines as the increase in the internal energy of the material.

When ever heat is given to the material, the atoms and the molecules in the material gains energy and moves with a kinetic energy.

The increase in kinetic energy allows the atoms and the molecules to move with higher velocities in the material, and they collide with each other, thus the temperature of the material increases.

Thus the thermal energy is related to the kinetic energy of atoms, ions, and molecules.

To know more about Thermal energy follow

https://brainly.com/question/19666326

The resistance is 15 ohms.

Also, it's dissipating 960 watts whenever it's turned on. So it's almost as hot as a toaster, and Minh no longer has hands.

Answer:

19 km.

..............

Explanation:

.....

Answer:The Distance is 43 and displacement is 5km south

Explanation: To find the distance you add up all the numbers which was 43 and to fine the displacement subtract all the numbers and since all the other numbers were out expect for -5 which was south you would put 5 km south , if the number has a negative on it , it doesnt matter.

Answer:

The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.

Explanation:

First, we calculate the intensity ([tex]I[/tex]), in watts per square meter, by the Inverse-Square Law:

[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex] (1)

Where:

[tex]\dot W[/tex] - Power, in watts.

[tex]r[/tex] - Radius, in meters.

And the sound intenity level ([tex]L[/tex]), in decibels, is expressed by:

[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex] (2)

Where [tex]I_{o}[/tex] is the reference sound intensity, in watts per square meter.

If we know that [tex]\dot W = 135\,W[/tex], [tex]r = 10\,m[/tex] and [tex]I_{o} = 10^{-12}\,\frac{W}{m^{2}}[/tex], then we find that sound level at a distance of 10 meters is:

[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex]

[tex]I = 0.107\,\frac{W}{m^{2}}[/tex]

[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex]

[tex]L \approx 110.294\,dB[/tex]

The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.

Answer:

The final temperature is approximately 23.55°C

Explanation:

The given parameters are;

The mass of the ice block, m₁ = 20 g

The initial temperature of the block, T₁ = -65°C

The mass of the water to which the block is added, m₂ = 570 g

The mass of the copper container containing the water, m₃ = 76 g

The initial temperature of the water and the copper, T₂ = 26°C

The specific heat capacity of copper, c₃ = 387 J/(kg·°C)

The specific heat capacity of ice, c₄ = 2,090 J/(kg·°C)

The latent heat of fusion of ice, l = 3.33 × 10⁵ J/kg

The specific heat capacity of water, c₁ = 4,186 J/(kg·°C)

We have;

ΔQ = m₁·c₁·ΔT + m₁·l = m₂·c₂·ΔT + m₃·c₃·ΔT

Therefore, we get;

20 × 2,090 × -65 +  20 × 3.33 × 10⁵ + 20 × T × 4,186  = 570 × 4,186 × (26 - T) + 76 × 387 × (26 - T)

Using a graphing calculator, we get;

83720·T + 3943000 = 62801232 - 2415432·T

The final temperature, T ≈ 23.55 °C

Answer:

Up first are Mercury and Venus. Neither of them has a moon. Because Mercury is so close to the Sun and its gravity, it wouldn't be able to hold on to its own moon. Any moon would most likely crash into Mercury or maybe go into orbit around the Sun and eventually get pulled into it.

Answer: [tex]18.22\ cm[/tex] from [tex]3.5\ nC[/tex] charge.

Explanation:

Given

The magnitude of the first charge is  [tex]Q_1=3.5\ nC[/tex]

The magnitude of the second charge is [tex]Q_2=5\ nC[/tex]

[tex]-6\ nC[/tex] charge must be placed in between the two charges to establish equilibrium

The electrostatic force is given by

[tex]F=\dfrac{kq_1q_2}{r^2}[/tex]

Equilibrium will be established when force by both the charges balance out each other. Suppose [tex]-6\ nC[/tex] is placed at a distance of [tex]x[/tex] cm from [tex]3.5\ nC[/tex] . So, we can write

[tex]\Rightarrow \dfrac{k(3.5)(-6)}{x^2}=\dfrac{k(5)(-6)}{(40-x)^2}[/tex]

Canceling similar terms

[tex]\Rightarrow \left [ \dfrac{40-x}{x}\right ]^2=\dfrac{10}{7}\\\\\Rightarrow \dfrac{40-x}{x}=\sqrt{\dfrac{10}{7}}=1.195\\\\\Rightarrow 40-x=1.195x\\\Rightarrow 40=2.195x\\\Rightarrow x=18.22\ cm[/tex]

Thus, the equilibrium position is [tex]18.22\ cm[/tex] from [tex]3.5\ nC[/tex] charge.

Answer:

What school do you go to?

Explanation:

Answer:

Yes, but its magnetic power is very weak so its not that noticeable to the average person whos not paying attention.

Answer:

A workout injury can happen to anyone, no matter your experience or fitness level. People hurt themselves in all kinds of ways when they work out. Even walking can cause an injury. But you can significantly cut your risk of getting hurt by following certain workout precautions. There are simple steps that can help keep you injury-free during your workout.

Every workout should begin with a warm-up and end with a cool-down period. A warm-up helps your body get ready for exercise. It gradually increases your heart rate and loosens your muscles and joints. Cool-down after you work out so, it brings your heart rate back to normal. Walking for 5 to 10 minutes after you work out is one way to cool down. Do dynamic stretching before and after you work out. This will help increase flexibility. Don't push yourself too hard. As your fitness abilities increase and you will be able to challenge yourself more.

Hope this helps

Maintaining physical fitness is very important in today's world. Each and everyone should be involved in physical fitness.nowaday people are so busy with their work that they have forgotten health is wealth.

Even if we get engaged in physical fitness activity we can some time get insuries . some of tips that can help prevent from getting physical fitness injury, warm up exercises should be done before exercise to avoid muscle strength.safety precautions should be taken if you are dealing with heavy objects .

hence we should maintain physical fitness with getting rid of injury that may occur

mark me

Answer:

The momentum, ΔP, and therefore, kinetic energy given to the ball in a serve is the result of the product of the tension force, 'F', in the string and the time of contact, Δt, between the ball and the string

ΔP = F × Δt

Explanation:

The impulse, ΔP, is the produce of the force, 'F', applied to a body for a given period of time, Δt', that gives motion to the body, and it is equal to the change of momentum of the body

ΔP = F × Δt

The momentum, 'P', of a body is the product of the mass, 'm', of the body and its velocity, 'v'

P = m × v

Tension is the axial pulling force of a string

T = Axial Force, F[tex]_{axial}[/tex]

The tension used in Tennis Racket strings is between 40 to 65 lbs.

When high tension is used in the string, the string is taut, and the contact duration between the Racket string and the ball is minimal, and the player needs to use more force to obtain a high momentum, and therefore, energy in the ball, which reduces control, and increase stress, as force is more emphasized

When low tension is used in the string, the Tennis Racket strings are more elastic. During a serve, the ball pushes the strings further back into the racket, such that the ball spends more time in contact with the string, (Δt is larger), and therefore, the impulse, F·Δt = ΔP, given to the ball is larger, therefore, the ball has a larger change in momentum, and therefore more energy in the intended direction.

However, a very slackened string will increase the increase area and time (large Δt) of contact of the ball and the racket such that the force given to the ball, F = ΔP/(large Δt) is reduced and therefore reduce the likelihood of gaining points from a serve against an opponent with a much forceful return of a serve.

Explanation:

Wave motion

ex...longitudinal wave.

Answer:

it means that velocity of a body rises by 9.8m/s each second if the air resistance is nrelated

mark me

Explanation:

Given that,

Mass of a truck = 15,000 kg

Speed of the truck = 25 m/s

Mass of car = 1,100 kg

Speed of the car = 15 m/s

As they stick together after the collision. Let V be the speed after the collision.

Initial momentum of the system,

[tex]P_i=15000\times25+1100\times15\\\\=391500\ kg-m/s[/tex]

Final momentum of the system,

[tex]P_f=(15000+1100)V\\\\=16100V[/tex]

Hence, this is the required solution.