Examples of pure substances are elements and _________.

A. Mixtures
B. Compounds

Answers

Answer 1

Answer:

b

Explanation:

Answer 2

Answer:

b

Explanation:

trust


Related Questions

Nitrogen-14 has 7 protons. How many neutrons does it have?

Answers

Answer:

7

Explanation:

Using information found on the Periodic Table of Elements:

Nitrogen contains 7 protons, 7 neutrons, and 7 electrons.

..

Atomic number is 7

Atomic mass is 14

The mass number is the sum of protons and neutrons in the nucleus.

=> You can subtract the atomic number from the mass number to find the number of neutrons.

When you have two materials with the same index of refraction, it means that

Answers

Answer:

When you have two materials with the same index of refraction, it means that if they are touched by a ray of light it won't have a chance, and its form would prevail.

Explanation:

The reason behind this is that in the first place. When light passes through an object of certain refraction it is modified from its natural state, allowing it to change in color to the human eye or many other effects in other perceptive elements. However, when the same light passes through two objects with the same refraction due to their physical characteristics, it doesn't change because once it comes out of the first one it will suffer the same effect from the last one. For it to change the refraction would have to be higher or lower. Then it would be modified. The reason is because the dimensions are not modified. Because at some point the ray of light has to come out of the first one to enter the second one.

Select the correct answer.
The motion of a car on a position-time graph is represented with a horizontal line. What does this indicate about the car's motion?
А.
It's not moving
B.
It's moving at a constant speed.
It's moving at a constant velocity
D. It's speeding up.

Answers

Answer:

a

Explanation:

Answer:

its a because its the only thing not moving

Explanation:

Choose the best definition for velocity
1. How fast something is going
2. Speed in a certain direction
3. Which direction something is going
4. Something speeding up

Answers

It’s speed in a certain direction.

can someone tell me the answer for both of these pleaseeee i need it asap!!! i will give brainlist!!

Answers

Answer:

1/ decreases

2/ yes;

In general there is no relationship, and any combinations of frequencies and amplitudes are allowed.

Explanation:

Explanation for 1/ - please see the picture attached below

please answer I'll give brainlist
Assuming the sound wave moves with the speed of air ( 340 m/s), what is the wavelength of the wave?

Answers

Answer:

suppose frequency of sound = 100Hz

then wavelength = speed/ frequency

= 340/100= 3.4 m

A wave of wavelength 0.3 m travels 900 m in 3.0 s. Calculate its frequency.

Answers

Answer: 1000 Hz

Explanation:

You can calculate frequency by dividing velocity by wavelength

Frequency = velocity/wavelength

Find velocity first.

900 m/3 s = 300 m/s

Plug values in to find frequency.

F = (300 m/s)/0.3 m

F = 1000 Hz

A car takes 15 minutes to travel along a road that is 20 km long.
What is the average speed of the car?
A. 75 km/h B. 5.0 km/h C. 80 km/h D. 300 km/h

Answers

Answer:

C

Explanation:

15. 20

x4. x4

60. 80

80km/h

Answer:

80km/h

Explanation:

solution

given

d=20km

t=15min/60min=0.25h

s=?

s=d/t

s=20km/0.25h

s=80km/h

Un recipiente contiene 2,5 moles de gas propano. Calcula, utilizando la definición de mol, cuántas moléculas de propano (C3H8) contiene ese recipiente.


POR FAVOR NO LO ENTIENDO Y CON SUS OPERACIONES PLISS

Answers

Answer:

1.505*10^{24}  molecules

Explanation:

The number of molecules is independent of the subtance, and only depends on the number of moles.

To calculate the number of molecules in a substance with n moles you use the following formula:

[tex]m=nN_A[/tex]

m: number of molecules

NA: Avogadro's number = 6.02*10^23 molecules/mol

n: moles of the substance = 2.5 mol

You replace the values of n and NA in the equation for m and you obtain:

[tex]m=(2.5mol)(6.02*10^{23}molecules/mol)\\\\m=1.505*10^{24}\ molecules[/tex]

hence, the number of molecules is 1.505*10^24

On a sky coaster (human pendulum) that reaches 20 meters from it's equilibrium position, a man of 70 kg is able to reach a maximum speed of

Answers

Answer:

Explanation:

Using the principle of conservation of energy, the potential energy is converted to kinetic energy, assuming any losses.

Kinetic energy is given by ½mv²

Potential energy is given by mgh

Where m is the mass, v is the velocity, g is acceleration due to gravity and h is the height.

Equating kinetic energy to be equal to potential energy then

½mv²=mgh

V

Making v the subject of the formula

v=√(2gh)

Substituting 9.81 m/s² for g and 20 m for h then

v=√(2*9.81*20)=19.799 m/s

Rounding off, v is approximately 20 m/s

Answer:

19.8 m/s

Explanation:

During the motion of a pemdulum bob, it casually converts kinetic energy to potential energy and vice versa.

A pendulum bob reaches its maximum speed at a position closest to its equilibrium position and has its lowest when it is farthest from the equilibrium position.

The maximum speed of a pendulum bob based on the mass involved and the maximum displacement from the equilibrium position is obtained from

Maximum kinetic energy = Maximum potential energy

Maximum potential energy occurs at the farthest point from equilibrium, that is,

P.E(max) = mgh

Maximum kinetic energy = ½mv²

½mv² = mgh

v = √2gh

g = acceleration due to gravity = 9.8 m/s²

h = farthest height from equilibrium position = 20 m

v = √(2×9.8×20) = 19.8 m/s

Hope this Helps!!!

A circuit has a current of 3 A. How many coulombs of charge will pass by a point in the circuit in 2 seconds?

- 6C

- 5C

- 3/2 C

- 2/3 C

One of these are the answer..

Answers

Answer:

6C

Explanation:

The quantity of charge, Q, passing through an electric circuit is dependent on the electric current, I, and the time taken, t, for the current to flow. It is given mathematically as follows

Q = I x t          ------------------------------(i)

Where;

I is measured in Amperes(A)

t is measured in seconds (s)

Q is measure in coulombs (C)

From the question,

I = 3A

t = 2s

Substitute these values into equation (i) as follows;

Q = 3 x 2

Q = 6C

Therefore, the number of coulombs of charge that will pass is 6C

Is jump rope a sport.

Answers

Answer:

yes

Explanation:

Answer: Yes
Explanation:.

At a grocery store, 20 fl oz of brand A vitamin
water is sold for $0.95. What is the unit price of
the vitamin water per ounce, to the nearest cents?

Answers

Answer:

0.05 cents per fl oz

Explanation:

0.95 divided by 20

0.0475 to the nearest cent 0.05

A 1200 kg car accelerates from 13m/s to 17m/s. find the change in momentum of the car?

Answers

Answer:

4800

Explanation:

The change in velocity of the car is 17-13=4m/s. Since the change in momentum is the mass multiplied by the change in velocity, the answer is 4*1200=4800. Hope this helps!

The change in momentum will be "4800".

Given:

Mass,

m = 1200 kg

Change in velocity,

Δv = 17-13

            =  4 m/s

Now,

The change in momentum is:

= [tex]Mass\times Change \ in \ velocity[/tex]

= [tex]1200\times 4[/tex]

= [tex]4800[/tex]

Thus the above answer is correct.

Learn more about momentum here:

https://brainly.com/question/8644950

explain nuclear fusion briefly

Answers

Answer:

Nuclear fusion is the process in which two atomic nuclei are fused together into a larger single nucleus, releasing energy in the process. ... In proton-proton fusion, four hydrogen atoms are fused into a single helium-4 atom, releasing a lot of energy in the process.

Explanation:

Un semáforo de 80N cuelga del punto medio de un cable de 30m tendido entre 2 postes. Halle la tensión en cada segmento del cable si éste tiene un pandeo que lo hace descender una distancia vertical de 1m

Answers

Answer:

T1 = T2 = 602.33 N

Explanation:

I attached an image of the forces diagram below.

The x component of the forces for this cases is:

[tex]\Sigma F_x=T_1cos\theta-T_2cos\theta=0\\\\T_1cos\theta=T_2cos\theta\\\\T_1=T_2[/tex]

And the y components:

[tex]\Sigma F_y=T_1sin\theta+T_2sin\theta-W=0\\\\T_1=T_2=T\\\\\Sigma F_y=2Tsin\theta=W\\\\T=\frac{W}{2sin\theta}[/tex]

The angle is calculated by using the information about the length of the cable and the vertical distance of the traffic light:

[tex]\theta=tan^{-1}(\frac{1}{15})=3.81\°[/tex]

Thus, you obtain:

[tex]T=\frac{80N}{2(sin3.81\°)}=601.33N[/tex]

hence, the tension in both segments of the cable is 602.33 N

This diagram shows a baseball’s motion. Which statement is best supported by the diagram?

a
Maximum Gravitational potential energy is at point R.
b
Kinetic energy becomes potential energy between points P and Q.
c
Kinetic energy becomes potential energy between points R and S.
d
Maximum kinetic energy is at point R.

Answers

Answer:

A

Explanation:

maximum gravitional potential energy is at point R

A. Maximum gravitational potential energy is at point R.

What type of phase change occurs when water vapor in the atmosphere changes to liquid water in clouds?

Answers

Answer:

condensation, the process of changing from a gas to a liquid

A charge of 80 coulombs passes through a circuit in 5 seconds. What is the current through the circuit?

Answers

Answer:

I = 16amp

Explanation:

Charge coulomb ( Q ) = It

Where I =current in ampere

t = time = 5 seconds

80 = I × 5

I = 80/5

I = 16amp

The current through the circuit will be I = 16amp

Se tienen 2 vectores cuyos módulos están en la misma razón que 5 y 2. Si cuando forman 53º su resultante mide 3√29u, ¿Cuánto mide el mayor vector?

Answers

Answer:

|v2| = 3.27

Explanation:

You have two vector v1 and v2. The relation between the magnitudes of both vectors is given by:

[tex]\frac{|v_1|}{|v_2|}=\frac{5}{2}[/tex]

Furthermore, the projection (the dot product) of one vector on the other one is given by the following formula:

[tex]v_1 \cdot v_2 = |v_1||v_2|cos\theta[/tex]

The dot product between v1 and v2 is 3√29. If you multiply the right hand side of the last equation by |v2|/|v2| you obtain:

[tex]3\sqrt{29}=\frac{|v_1|}{|v_2|}|v_2|^2cos(53\°)[/tex]

you do |v2| the subject of the formula:

[tex]|v_2|=\sqrt{\frac{|v_2|}{|v_1|}\frac{3\sqrt{29}}{cos53\°}}\\\\|v_2|=\sqrt{\frac{2}{5}\frac{3\sqrt{29}}{cos53\°}}=3.27[/tex]

30
. Which of the following represents the
statement "The difference of two square
numbers is positive​

Answers

Answer:

In mathematics, the difference of two squares is a squared (multiplied by itself) number subtracted from another squared number. Every difference of squares may be factored according to the identity. in elementary algebra.

Explanation:

8000 kg engine pulls a train of 5 wagons, each of 2000 kg, along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate the net accelerating force

Answers

Answer:

The net force of engine on total mass of train is 35000 N

The net acceleration is 1.944 m/s²

Explanation:

Here we have;

Mass of each wagon of train = 2000 kg

Number of wagons = 5

Total mass of wagons = 5 × 2000 = 10000 kg

Mass of engine = 8000 kg

Total mass, m of train (engine plus wagons) = 10000 + 8000 = 18000 kg

Force exerted by train = 40000 N

Friction force due to the railway track = 5000 N

Net force, F of engine on total mass of train = 40000 - 5000 = 35000 N

Formula for force, F = Mass, m × Acceleration, a  

35, 000 = 18,000 × a

a = 35,000/18,000 = 35/18 m/s²

[tex]a = 1\tfrac{17}{18} \ m/s^2[/tex]

The net acceleration = 1.944 m/s².

how do braces protect you while doing sports

Answers

Answer:

they don't, if you get hit in the face then the brackets are gonna rub up against the inside of your mouth then you'll bleed

Explanation:

Which happens during the day at the beach?

A. The water is warmer than the land, and air sinks over the water

B. The water is cooler than the land, and air sinks over the water

C. The water is warmer than the land, and air rises over the water

D. The water is cooler than the land, and air rises over the water

Answers

Answer:

c

Explanation:

not sure i think heating beach

What has an ionised atom lost or gained?
Protons
Gamma Rays
Electrons
Neutrons

Answers

Answer:

Electrons

Explanation:

Ionised atoms loose and gain electrons.

hope it helps!

A skier reaches the end of a 0.9 km track in 1.5 hours, at what speed does it travel?
(Please help,I need the answer as soon as possible)

Answers

Speed = Distance/Time

S = D/T

D = 0.9Km, T = 1.5hours,

S = 0.9/1.5

S = 0.6 m/s

hope it helps!

Answer: Speed =

distance = 0.9 * 1000 = 900 metres, because speed is measured in m/s so the km has to be converted to m

time = 1.5 * 60 = 90 seconds , because speed is measured in m/s so the time in minutes(m) has to be converted to seconds(s)

Speed =

          = 10m/s

Read more on Brainly.com - https://brainly.com/question/11367821#readmore

Explanation: I don't know what this is but this is what I found and I hope it's helpful

What is motion ,terms used to measure motion ,examples etc

Answers

Answer:

A physic term

Explanation:

Answer:

Cambio de lugar o de posición de un cuerpo en el espacio.

Explanation:

scientific notation for 836

Answers

Answer:

8.36e2

Explanation:

Use a scientific calculator

Its notation is written as :

8.36 x 10^2

Which energy output objects work with the turbine?

Answers

Alternator (generator)

The passage helps the reader to draw conclusions about which character's perspective? ºAlec ºAlice ºAlec's father ºAlec's mother

Answers

Answer:

I think it might be A: Alec but tell me if I'm wrong

Explanation:

Answer:

a

Explanation:

i did it on e d g e n u i t y

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