100 points!!! Please help!!!
In the system shown above, the pulley is a uniform disk with a mass of .75 kg and a radius of 6.5 cm. The coefficient of friction between the 5.8 kg mass and the horizontal surface is .25, and the ropes does not slip on the pulley. They system is released from rest. Use work-energy principles to determine the kinetic energy of the (a) 2.8 kg mass and (b) the pulley after the 5.8 kg mass has moved 2.2 meters.

Answer:

R = 4Ω

Explanation:

If we have two resistors with resistances R1 and R2 in series the total resistance is R = R1 + R2

If the resistances are in parallel, the total resistance is given by:

1/R = 1/R1 + 1/R2.

First, we have a resistor with R1 = 1.5Ω

This resistor is connected in series with a parallel part (let's find the resistance of this parallel part), in one branch we have two resistors in series with resistances:

R2 = 8Ω and R3 = 4Ω

Because these are in series, the resistance of that branch is:

R = 8Ω + 4Ω = 12Ω

In the other branch, we have a single resistor of R4 = 4Ω

The resistance of the parallel part is:

1/R = 1/12Ω + 1/4Ω = 1/12Ω + 3/12Ω = 4/12Ω = 1/3Ω

1/R = 1/3Ω

R = 3Ω

Then we have a resistor (the first one, R1 = 1.5Ω) in series with a resistor of 3Ω.

Then the total resistance is:

R = 1Ω + 3Ω = 4Ω

Answer:

b is the correct answer

Explanation:

Answer:

the ball's was lowered because of the gravitational force and because of the friction force's

By compressing the spring a distance x (in m), you are storing 1/2 k x ² (in J) of potential energy, which is converted completely into kinetic energy 1/2 m v ², where

• k = 40 N/m = spring constant

• m = 10 kg = mass of the ball

• v = 2 m/s = ball's speed (at the moment the spring returns to its equilibrium point)

So we have

1/2 k x ² = 1/2 m v ²

x = √(m/k v ²) = √((10 kg) / (40 N/m) (2 m/s)²) = 1 m

Answer:

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Answer:

f nothing can move faster than spped of light.

Explanation:

Answer:

Explanation:

moment of inertia of flywheel = 1/2 m R²

= .5  x 1500 x .6²

= 270 kg m²

If required angular velocity be ω

rotational kinetic energy = 1/2 I ω²

= .5 x 270 x ω² = 135 ω²

kinetic energy of bus when its velocity is 20 m/s

= 1/2 x 10000 x 20²

= 2000000 J

Given 90 % of rotational kinetic energy is converted into bus's kinetic energy

135 ω² x 0.9 = 2000000 J

ω²=16461

ω = 128.3 radian /s

b )

Let the height required be h .

Total energy of bus at the top of hill = mgh + 1/2 m v²

m ( gh + .5 v²)

= 10000 ( 9.8h + .5 x 3²)

From conservation of mechanical energy theorem

10000 ( 9.8h + .5 x 3²) = 2000000

9.8h + .5 x 3² = 200

9.8h  = 195.5

h = 19.95 m .

Answer:

3 gm / cm^3

Explanation:

Density = weight / volume

90 / 30 = 3 gm/cm^3

first. this is only worth 38 points second it's B

Answer:

Explanation:

Answer:

a)   v = 0,  a = - 15 pi²

b) v = - 40.8 cm / s,  a = -74.2 cm / s

Explanation:

the simple harmonic motion is described by the expression

        x = A cos (wt + Ф)

in that case they indicate the amplitude of the movement

        A = 15 cm

angular velocity and period are related

        w = 2π / T

         w = 2π/ 2

         w = π rad / s

speed is defined by

         v = dx / dt

          v = -A w sin (wt + Ф)

acceleration is defined by

         a = dv / dt

         a = - A w² cos (wt + Ф)

In order to evaluate this expression we must know the value of the phase constant (Ф) that meets the initial conditions, the most common thing is that the system is released, v = 0 for y = 0 s, let's use the speed equation

          v = -A w sin (0+ Ф)

for this expression to be zero, the sine must be zero, so

         Ф= 0

now let's write the equations for our case

         v = - 15 π sin (π t)

         a = - 15 π² cos (π t)

a) for x = 0

          v = 0

          a = - 15 pi²

b) for x = 7.5 cm

Let's find out how long it takes to get to this position

          x = 15 cos (π t)

          7.5 / 15 = cos π t

          pi t = cos⁻¹ 0.5

          t =  1.047/π

don't forget that the angles are in radians

          t = 0.333 s

now let's look for speed and acceleration

         v = - 15 π sin (π 0.333)

         v = - 40.8 cm / s

         a = - 15 π² cos (π 0.333)

         a = -74.2 cm / s

Answer:

The system has two solutions:

(1, -1) and (0, 0)

Explanation:

We have the system of equations:

x + y = 0

x = x^2 + 2*x*y

To solve this, the first step is to isolate one of the variables in one of the equations, I will isolate x on the first one.

x = -y

Now we can replace this on the other equation, to get:

x = x^2 + 2*x*y

(-y) = (-y)^2 + 2*(-y)*y

Now we can solve this equation for y.

-y = y^2 - 2*y^2

-y = -y^2

y^2 - y = 0

We can solve this using the Bhaskara's formula:

The solutions are then:

[tex]y = \frac{-(-1) \pm \sqrt{(-1)^2 - 4*1*0} }{2*1} = \frac{1 \pm 1}{2}[/tex]

Then the two possible solutions are:

y = (1 + 1)/2 = 1

and

y = (1 - 1)/2 = 0

Suppose that we take the first one, y = 1.

Then the solution for x is given by "x = -y"

Then:

x = -1

This means that one solution of the system is (-1, 1)

If we take the other solution for y, y = 0

The value of x will be:

x = -y = -0 = 0

Then another solution of the system is (0, 0)

Answer:

C: 3.93 x 10^22 free electrons

Explanation:

The no. of free electrons can be found out using the following formula:

[tex]N = V\rho\\[/tex]

where,

N = No. of free electrons = ?

V = Volume = 2.55 cm³

ρ = density of electrons = 1.54 x 10²² free electrons/cm³

Therefore, using these values in the equation, we get:

[tex]N = (2.55\ cm^3)(1.54\ x\ 10^{22}\ free\ electrons/cm^3)\\[/tex]

N = 3.93 x 10²² free electrons

Therefore, the correct option is:

C: 3.93 x 10^22 free electrons

Answer:

Mass (m) = 5.4 kg

Force (f) = 20 N

Acceleration (a) = ?

Acceleration= m × a

[tex]m \times a \\ = 5.4 \times 20 \\ = 108 \: ms ^{ - 2} [/tex]

=> The resulting acceleration of the object is 108 m/s².

Answer: Moisture and food (bread)

Explanation:

Mould grows best in humid, damp air/wet conditions.

Since the bread is moist it will provide humidity for the mould as well as food.

A container with a cover would not be a favoring condition as mould needs oxygen to grow and survive.

Answer:

Explanation:

This is because polythene rod is an insulator , therefore when it is rubbed with a cloth , electrons move easily therefore making it charged but

Metal rod is a conductor, it conduct heat . Therefore, their atoms have electrons that is constantly in motion. Therefore rubbing it with a cloth will make any difference in making it charged because it have very huge number of stable electrons which will not allow more electrons to move through them.

Answer:

The tank appears to be 3 m deep only. Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams.

Miniature circuit breakers is called the developed form of fuse because MCBs are more sensitive to current than fuses. They immediately detect any abnormality and switch off the electrical circuit automatically. This prevents any permanent damage to electrical appliances and human beings

Answer:

kilogram metre per second square

Solution :

Crust

In the field of geology, the crust may be defined as the outermost solid shell of a planet. It forms the topmost outer hard layer of the earth surface. Earth has three layers. They are the crust, mantle and the core.

When we go deeper and deeper inside the earth's crust, the temperature rise. In the crust, on the surface of the earth, the temperature is normal and is atmospheric. As we go deep down the core, the temperature rise and it is highest at the core where all the rock and the iron is in the form of the molten lava.

According to the Geologist, beneath the earth's crust, for every mile we go inside the temperature rises by 15 degree Fahrenheit.

Answer:

It happened less than 8 hours ago.

Explanation:

Over the first eight hours, the body begins to stiffen but is still flexible.

Answer:

The apparent power is the power delivered to a load without considering the effects of the power-factor angle of the load

Explanation:

If I and V are the current and voltage across the load, the apparent power, = IV

Since,

apparent power = active power + reactive power

active power = IVcosФ

reactive power = IVsinФ

So, IV = IVcosФ + IVsinФ

where I = current, V = voltage and Ф = power factor angle.

We see that the apparent power is the product of the current, I and the Voltage, V without considering the power factor angle of the load.

So, the apparent power is the power delivered to a load without considering the effects of the power-factor angle of the load.

Answer:

No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur in a specific area within a certain number of years.

Answer:

No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur in a specific area within a certain number of years.

Explanation:

Answer:

Explanation:

High pitch:

-birds chirping

-nails on a chalkboard

-flies buzzing

-children squealing

-whistle

Low pitch:

-thunder

-dogs barking

- earthquakes

-  bass drum,

-cannon shot,

5 example of high pitch sound

baby crying , whistle ,  school bell , fire alarm , chirping of birds

5 example of low pitch sound

thunder , drum , earthquake , generator , animal roar

It is the effect or sensation produce in brain due to sound of some particular frequency

5 example of high pitch sound

baby crying , whistle ,  school bell , fire alarm , chirping of birds

5 example of low pitch sound

thunder , drum , earthquake , generator , animal roar

learn more about pitch :

https://brainly.com/question/20382587?referrer=searchResults

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Answer:

dissociation of acetic acid (like vinegar) in water

Explanation:

CH3COOH is basically vinegar (aka acetic acid)

dissociation of acetic acid in water

so when you put vinegar in water it makes 2 hydrogen ions (H+) and acetate ( CH3C00 ) a chemical that used in making film

Answer:

The most widely accepted theory for the formation of fossil fuel is that fossil fuel was formed over time from decaying organic matter. Organisms died and were buried in the ground millions of years ago.

Explanation:

g00gle answer! so change it up a little :P

hope this helps :)

Answer:

True, wheel and excel has co-axial cylinder. true or false.

You can follow me to get more answer.

Answer:

true

Explanation:

yes they have two com xial cylinder and they work together

Answer:

Nylon is a generic designation for a family of synthetic polymers composed of polyamides.

Explanation: