can someone please solve this

Answer:

3 gm / cm^3

Explanation:

Density = weight / volume

90 / 30 = 3 gm/cm^3

Answer:

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

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

#SPJ2

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:

El área de la placa más grande es aproximadamente 9,81 veces el tamaño del área de la placa más pequeña

Explanation:

Los parámetros dados son;

La fuerza aplicada sobre la placa más pequeña, F = 40 N

El culo del objeto levantado en la placa más grande, m = 40 kg

El peso del objeto, W = 40 kg × 9,81 m / s² = 392,4 N

Tenemos la presión en el plato pequeño = La presión en el plato más grande

Por lo tanto;

F / A₁ = W / A₂

Dónde;

A₁ = El área del plato pequeño

A₂ = El área de la placa más grande

Por lo tanto, obtenemos;

40 N / (A₁) = 392,4 N / (A₂)

A₂ / A₁ = 392,4 N / (40 N) = 9,81

∴ A₂ = A₁ × 9,81

El área de la placa más grande, A₂ = 9,81 (9,81 m / s² ≈ g) multiplicado por el área de la placa más pequeña A₁.

Answer:

kilogram metre per second square

D. Chemical energy stored in the bonds of the molecules of the sandwich is transformed into kinetic energy. This statement describes the energy transformation that occurs when a person eats a sandwich to gain energy for a long hike

Law of energy conservation states that energy can neither be created nor be destroyed and can only transform from one form to other form.

From Law of energy conservation we can say that Digestion starts from that very point when we put food in our mouth so the moment you eat the sandwich, it starts getting digested and when it reaches the stomach ,your body converts its chemical energy into the movement of your muscles.

hence , correct option is :

D. Chemical energy stored in the bonds of the molecules of the sandwich is transformed into kinetic energy.

learn more about Law of energy conservation  :

https://brainly.com/question/12050604?referrer=searchResults

#SPJ2

Answer: True

no matter can be created nor destroyed in any process. if something is burned, made in a compound or anything like that all matter is still the same amount from beginning to end.

Explanation:

Answer:

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

Explanation:

Answer:

िििििििििििििििििििििििििोोोोोोोोोोोोोोोोोोो

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 is 47.14 v

by the relation

[tex]\frac{V out}{V in } = \frac{N secondary}{N primary }[/tex]

Answer:

f nothing can move faster than spped of light.

Explanation:

Answer:

If you are talking about the experiment in which mouse and plants are kept in a closed glass jar in sunlight so in that case, they both survive because the CO2 released by the respiration of mouse is being utilized by the plants and fixed ( phosynthesis) and O2 is released as by product, which is taken by the mouse for respiration.

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:

It spins on the side where it looks shiny.

Explanation:

Answer:

9120-25600 RPM mate

Explanation:

I know your thinking it's crazy because of the other answer. but don't worry i looked it up for ya.

Answer:

Explanation:(a)Mercury Barometer and Aneroid Barometer

(b)Gypsum

(c)Near point of human eye is 25 cm and the far point is infinity.

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

Answer:

Explanation:

Answer:

the velocity is decreasing therefore acceleration is negative

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:

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:  ultraviolet

Explanation:

Answer:

The Answer is gonna be A. It will speed up

Explanation :if it has the same velocity it will only change if the weight is less

This is the Answer

I hope I helped

I hope you are having a great day :3:3:3:3:3:3

Answer:

B

Explanation:

Why would it speed up if it is the same velocity??

It would stay at teh same speed. It would only increase if it weighed less.

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 :)

The question (obtained from the internet);

Cleo stated that light travels through air in straight paths, and when it moves from air to water, light changes direction, speeds up, and bends towards the normal

Answer:

The statement that best describes Cleo's mistake is;

Light slows down when it moves from air into water

Explanation:

The question;

Cleo stated that light travels through air in straight paths, and when it moves from air to water, light changes direction, speeds up, and bends towards the normal

The speed of light in water = 225,000 km/s

The speed of light in air = 299,702,547 m/s

The speed of light in vacuum = 299,792,458 m/s

Therefore, light slows down when it moves from a less dense medium to a denser medium

Light moves closer (bends) towards the normal when it moves from air into water. Light therefore, changes direction, and light moves in straight path which is known as rectilinear motion

Therefore, the statement that describes Cleo's mistake is that light actually slows down when it moves from air into water.

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 average depth of the ocean is about 12,100 feet.

Explanation:

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