what is an echo?
give me an short answer

Explanation:

Density=mass/volume

mass=x

10.49=X/12.99

X=10.49 X12.99

X=136.29657

mass=136.3g/cm^3

I hope it helped.

Answer:

Milk Lactometer

Milk Lactometer: A lactometer is an instrument that is used to check for the purity of milk by measuring its density.

lactometer is used to determine the purity of milk

hope it is helpful to you

Answer:

Halos, blurriness, and night blindness causes night vision (symptoms) while vitamin-A,corrective lenses, such as eyeglasses or contacts, can improve or help night vision.

Explanation:

I bet you will get full Marks if you write it!!

(please note that you will have to mark me as brainliest if it helped you)£

Answer:

[tex]n=1.86*10^{-30}m^3[/tex]

Explanation:

From the question we are told that:

Fermi energy of conduction electrons [tex]E_f=0.548J[/tex]

Generally the equation for Fermi energy is mathematically given by

 [tex]E_f=\frac{3}{\pi}^2/3*\frac{h^2}{8m}*{n^{2/3}}[/tex]

 [tex]E_f=\frac{3}{\pi}^2/3*\frac{h^2}{8m}*{n^{2/3}}[/tex]

 [tex]{n^{2/3}}=\frac{E_f}{\frac{3}{\pi}^2/3*\frac{h^2}{8m}}[/tex]

Where

h= Planck's constant

 [tex]{n^{2/3}}=\frac{E_f}{\frac{3}{\pi}^2/3*\frac{h^2}{8m}}[/tex]

 [tex]{n^{2/3}}=\frac{0.548J}{3.62*10^{-19}}[/tex]

 [tex]n=(1.51*10^{-20})^{3/2}[/tex]

 [tex]n=1.86*10^{-30}m^3[/tex]

Lifting an object and becomes potential energy of the object (Earth system). The change in gravity potential energy, ΔPEg, is ΔPEg = mgh.

With h being the increase in height and g the acceleration due to gravity.

I hope this helped :T

Answer:

Fast and Energetic

Explanation:

The game of floor hockey is primarily a Fast and Energetic game. The main objective of the game of field hockey is to score more goals than the opposing team by shooting the Hockey ball into the goal post of the opposing team,  Field hockey is similar to Ice hockey but the major difference is that Filed hockey is played without skates

Answer:

Solid objects will deform when adequate loads are applied to them; if the material is elastic, the object will return to its initial shape and size after removal. This is in contrast to plasticity, in which the object fails to do so and instead remains in its deformed state.

Explanation:

Answer:

It is false

Explanation:

because when it like a rolling ball it can deform no matter what unlesss you throw it at the ground really hard then it breaks but a soft or sometimes metal yeah it can deform but not all things solid deform.

Explanation:

On earth,

g=10 m/s^2

When M=2 kg,

weight on earth=2×10

=20N

When M=3.5 kg,

weight on Earth=3.5×10

=35N

When M=5kg,

weight on Earth=5.25×10

=52.5N

Answer:

When a polythene rod is rubbed with a duster, the friction causes electrons to gain energy. Electrons gain enough energy to leave the atom and 'rub off' onto the polythene rod. The polythene rod has gained electrons, giving it a negative charge.

Explanation:

Hope it helps

Answer:

immma send you the link friend me on hereExplanation:

Answer:

true is the answer of the question

Answer:

a. 90 dB

b. 80 dB

Explanation:

The given parameter of the sound is as follows;

The level to which the headphones are tuned = All the way up

The intensity of the sound of the headphones when tuned all the way up = 100 dB

a. The relationship between level change in loudness, ΔL, and the ratio of loudness, 'x', is presented as follows;

ΔL = 10·log₂(x) ≈ 33.22·log(x)

Therefore, for a sound to be half as loud, we have x = 1/2, therefore;

ΔL = 10·log₂(1/2) = 10·log₂(2⁻¹) = -10 ≈ 33.22·log(1/2)

The change in the intensity level for a sound half as loud, ΔL = -10 dB

Given that the sound was initially at 100 dB, the new level for a sound half as loud = 100 dB + ΔL = 100 dB - 10 dB = 90 dB

The decibel level the music must be set for a sound half as loud = 90 dB

b. In order for the sound to be 1/4 as loud, we have;

ΔL = 10·log₂(1/4) = 10·log₂(2⁻²) = -20

Therefore, the change in the level of the sound intensity level, ΔL by -20 dB will given a sound that is 1/4 as loud

The initial intensity level = 100 dB

The intensity level for a sound 1/4 as loud = 100 dB - 20 dB = 80 dB

Answer:

A battery is a device that stores chemical energy and converts it to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit. The flow of electrons provides an electric current that can be used to do work.

Answer: I believe that the answer is D.

Explanation:

Hope this helps and have a great day! :)

Answer:

D) all of the above

Explanation:

Answer:

120N

Explanation:

Weight=mass x acceleration due to gravity (on the planet)

Mass of an astronaut is 75kg and value of acceleration due to gravity on moon is 1.6m/s2

Weight of astronaut on moon=mass of astronaut x value of acceleration due to gravity on moon

75kg x 1.6m/s2

=120N

Answer:

Greatest gravitational energy is at "C".

The planet has to do work "against" the field to get to "C".

Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2  must decrease also to get to point C.

Answer: 75 N

Because we're finding the force, we need to use F = ma. M (Mass) = 25 and A (Acceleration) = 3. Multiply 25(3) to get 75. So, you're answer should be 75 N.

Answer:

Explanation:

For the see-saw to be balanced, take moment at the fulcrum:

40g * 3.5/2 = 120g * distance

distance = 1.167m from the center

Answer:

Gravitational potential=mgh

=50×10×2.5

=1250J

option a

Answer:

W = 439998 J = 439.99 KJ

Explanation:

First, we will calculate the acceleration of the car by using the first equation of motion:

[tex]v_f = v_i + at\\\\a = \frac{v_f-v_i}{t}[/tex]

where,

a = acceleration = ?

vf = final speed = [tex]108(\frac{km}{h})(\frac{1000\ m}{1\ km})(\frac{1\ h}{3600\ s})[/tex] = 30 m/s

vi = initial speed = [tex]36(\frac{km}{h})(\frac{1000\ m}{1\ km})(\frac{1\ h}{3600\ s})[/tex] = 10 m/s

t = time = 30 s

Therefore,

[tex]a = \frac{30\ m/s - 10\ m/s}{30\ s}[/tex]

a = 0.67 m/s²

Now, we will calculate the force applied by the engine:

F = ma

where,

F = force = ?

m = mass = 1100 kg

Therefore,

F = (1100 kg)(0.67 m/s²)

F = 733.3 N

Now, we will calculate the distance covered by the car by using the second equation of motion:

[tex]s = v_it+\frac{1}{2}at^2\\\\s = (10\ m/s)(30\ s)+\frac{1}{2} (0.67\ m/s^2)(30\ s)^2[/tex]

s = 600 m

Now, the work done (W) by engine can be calculated as follows:

W = Fs

W = (733.3 N)(600 m)

W = 439998 J = 439.99 KJ

Answer:

Hooke's law, given by [tex]F=-kx[/tex] is denoted with a negative sign to regard that the direction of restoring force that occurs opposite in direction of the force that caused the displacement [tex]x[/tex]. F represents the force required to create a spring displacement of [tex]x[/tex].

Explanation:

As with many things in physics, the negative sign represents direction. In this case, after a spring is displaced a distance of [tex]x[/tex] from equilibrium, the restoring force created by the spring will be in opposite direction of the force applied to move the spring there, represented by F.

Answer: A

Explanation: Edg2020

Answer:

I think the answer is Decreases the time that the egg slows down.

Explanation:

If not try it starts slowing down

O Increases the time that the egg slows down.

Answer:

v_f = -7.5 m / s

Explanation:

Let's analyze this exercise a little, two forces that act on a body for different time intervals are indicated, each force creates an impulse and since this is a vector quantity we must add in the form of vectors. The net momentum is

we assume that the direction to the right is positive

             I = I₁ + I₂

             I = F₁ Δt₁ - F₂ Δt₂

             I = 3  1.5 - 4  3

             I = -7.5   N s

now let's use the relationship between momentum and momentum, suppose the object starts from rest (vo = 0)

             I = Δp

             I = m (v_f - v₀)

             v_f = I / m

              v_f = -7.5 / m

to finish the calculation we must assume a mass m = 1 kg

              v_f = -7.5 m / s

the negative sign in the body is moving to the left

Answer:

using a seismograph

Explanation:

Answer:Shape

I took the quiz

Answer:shape

Explanation:

I took the quiz