help Plz, these questions are super confusing .

Answer:

Density, mass of a unit volume of a material substance. ... Density offers a convenient means of obtaining the mass of a body from its volume or vice versa; the mass is equal to the volume multiplied by the density (M = Vd), while the volume is equal to the mass divided by the density (V = M/d).

Explanation:

The International System of Units is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world

Answer:

Density is mass per unit volume

Explanation:

SI unit is kgm3

Answer: i think it is for 16,  Infectious diseases commonly spread through the direct transfer of bacteria. for 17 i think In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. i dont have a clue about the others but i hope this is right or atleast helps

Explanation:

Answer:

Explanation:

ice absorbs heat from the water. As the water molecules lose energy, they begin to slow down, and consequently to cool. So, it's kind of the opposite of what we might think: when we put ice in water, the ice doesn't give its cold to the water, it takes heat from the water.

Answer:

the vacoule in a plant is larger than that of an animal

Answer:

Hello There!!

Explanation:

Work done= force × distance moved

Work done=5000N×15m

Work done=75,000J

hope this helps,have a great day!!

~Pinky~

Answer:

I would say d I had the same question yesterday and I got it correct so hope that helps

Answer:

[tex]\mu=41.5\textdegree[/tex]

Explanation:

From the question we are told that:

Water index of refraction [tex]i_w=1.33[/tex]

Glass index of refraction [tex]i_g=1.50[/tex]

Generally the equation for Brewster's law is mathematically given by

 [tex]\theta=tan^{-1}(\frac{i_g}{i_w})[/tex]

 [tex]\theta=tan^{-1}(\frac{1.50}{1.33})[/tex]

 [tex]\theta=48.44 \textdegree[/tex]

Therefore Angle of incident to plane  \mu (normal at 90 degree to the surface)

 [tex]\mu=90\textdegree-\theta[/tex]

 [tex]\mu=90\textdegree-48.44\textdegree[/tex]

 [tex]\mu=41.5\textdegree[/tex]

Answer:

Pressure=Force/Area

F=50N

A= L x W

Change the units to metres

W= 0.2x10-³m

L= 12 x 10-²m

A= 0.2x10-³ x 12 x10-²

A=2.4x10^-5m²

P= 50/2.4x10^-5

= 2.08x10^6Nm-¹ ~ 2.1x10^6Nm-¹

Answer:

a)  

get mass of planet:  

ρ = M / V  

V = 4/3 * R_1^3  

M = ρ * V  

M = ρ * 4/3 * R_1^3  

equate force equations:

F = (GMm) / r^2     // r = R_2  

F = ma  

a = v^2/R_2  

F = m * (v^2/R_2)    

m * (v^2/R_2) = (GMm) / R_2^2  

plug in and solve v^2:  

m * (v^2/R_2) = (G * (ρ * 4/3 * R_1^3) *m) / R_2^2  

v^2 = (G * ρ * (4/3) * π * R_1^3) / R_2

put into kinetic energy equation:  

K = 1/2 * m * v^2  

K = 1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2

B)

givens:  

U = -(GmM) / R_2

plug in mass of planet:  

U = -(G * m * ρ * 4/3 * R_1^3) / R_2

C)

use previous equations and do some algebra:

K/U = (1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2) * -(R_2 / (G * m * ρ * 4/3 * R_1^3))  

K/U = -1/2

Answer:

True

Explanation:

Answer:

Explanation:

Use the equation

[tex]h(t)=-16t^2+v_0t+h_0[/tex]

where h(t) is the height after a certain amount of time goes by, v0t is the initial upwards velocity, and h0 is the initial height of the projectile. For us:

h(t) = 10

v0t = 80

h0 = 3 and filling in:

[tex]10=-16t^2+80t+3[/tex] and get everything on one side to factor:

[tex]0=-16t^2+80t-7[/tex]

This factors to

t = .09 sec and 4.9 sec. Let's interpret this.

The time of .09 is when the ball reached 10 feet on the way up, and

the time of 4.9 is when the ball reached 10 feet on the way back down. That's the height we need, 4.9 seconds.

Answer:

so a man counts 6 waves on a pound in 10 second

Explanation:

6×10 = 60

60/40

so the answer is3

Answer:

.0000004

Explanation:

The mass of a brick with a volume of 0.0006 m³ and a density of 1600 kg/m³ is 0.96kg.

The mass of a substance can be calculated by multiplying the density of the substance by its volume. That is;

Mass = density × volume

According to this question, the density of brick is 1,600 kg/m3 and it has a volume of 0.0006m³. The mass is calculated as follows:

Mass = 0.0006 × 1600

Mass = 0.96kg

Therefore, the mass of a brick with a volume of 0.0006m³ and a density of 1600 kg/m³ is 0.96kg.

Learn more about mass at: https://brainly.com/question/19694949

Answer:

garden

Explanation: All the other habitats are aquatic

Answer:

f / 8

Explanation:

The f-number is the ratio of the lens's focal length to its diameter and is a measure of the intensity of the light reaching the CCD. The smaller the greater the intensity of the light

           I = D / f

           f-number = f / D

           I = 1 / f-number

the energy deposited in the CCD is proportional to the intensity of the light and the exposure time (Δt)

          E = I Δt

          E = 1 /f-number   Δt

in the exercise they indicate that the system is well exposed (the image is sharp and clear) for fo-number = f / 16

        Δt = exposure time = 1/120 s

        E =   [tex]\frac{1}{120} \ \ \frac{1}{fo-number}[/tex]  

indicate that the exposure time has been changed to Δt = 1/60 s, which should be the f₁-number

        E = [tex]\frac{1}{60} \ \ \frac{1}{f_1-number}[/tex]

the energy deposited must be the same per location we can equal the expressions

          [tex]\frac{1}{120} \ \frac{1}{f_o-number} = \frac{1}{60} \ \frac{1}{f_1-number}[/tex]

         f₁-number = [tex]\frac{60}{120} \ \ \frac{1}{fo-number}[/tex]

         f₁-number = ½  16

         f₁-number  = 8

so the system should be set to f / 8

Answer:

 v = 220 m / s

Explanation:

This is a kinematics exercise, the expression for velocity is

          v = 25 t² - 80 t - 200

asks the velocity for time t = 6 s.

let's calculate

        v = 25 6² - 80 6 - 200

        v = 220 m / s

The velocity for the first six seconds when acceleration is zero is -44 m/s.

The velocity of an object is the rate of change displacement with time.

The velocity of the object for the first six seconds when the acceleration is zero is calculated as follows;

[tex]a = \frac{dv}{dt} \\\\a = 50t - 80\\\\0 = 50t - 80\\\\50t = 80\\\\t = 1.6 \ s[/tex]

Velocity when time = 1.6 s

[tex]v(1.6) = 25(1.6)^2 - 80(1.6) - 200\\\\v(1.6) = -264 \ m/s[/tex]

The velocity for the first six seconds when acceleration is zero.

[tex]v = v_{a =0} + v_6\\\\v = - 264 \ + 25(6)^2 - 80(6) - 200\\\\v = -44 \ m/s[/tex]

Learn more about velocity here: https://brainly.com/question/6504879

Answer:

Explanation:

I dont  have an explenation    

Answer: 170km/hr to the South

Explanation:

The resultant velocity of the plane ilwill be gotten by adding the value of the velocities of the plane with the tallwind. It should be noted that the direction of the wind is.takwn into consideration.

Therefore, the resultant velocity of the plane will be:

= 20km/hr + 150km/hr

= 170km/hr to the South

Answer:

Resultant Velocity = 20 km/h + 150 km/h = 170 km/h

Explanation:

Answer:

SiZe

Explanation:

bad bunny is the best!!!

Answer:

this pattern to occur there must be coherence in the light beams.

you use a flashlight, the rays are incoherent so diffraction patterns cannot occur.

Explanation:

The point pattern that appears in the wall is the result of the interference and diffraction processes through each space of the mesh, for this pattern to occur there must be coherence in the light beams.

The coherence process is that all the rays have the same constant and phase, before the appearance of the lasers, the light is stopped by a small opening and this ray is the one that passes through the slits, with the appearance of the laser this it is consistent from its production process, so opening is not necessary, with this there is much greater intensity and the measurement process is simplified.

When you use a flashlight, the rays are incoherent so diffraction patterns cannot occur.

Polarization has no effect on diffraction patterns so it does not matter if it is vertical or horizontal.

Answer:

Explanation:

The surface area of a star estimated by the energy emitted per sq meter yields the overall luminosity, which can be represented mathematically as:

[tex]L= 4 \pi R^2 \sigma T^4 --- (1)[/tex]

where;

L ∝ R²T⁴

and;

R = radius of the sphere

σ = Stefans constant

T = temperature

Also; The following showcase the relationship between flux density as well as illuminated surface area as:

[tex]F = \dfrac{L}{A}[/tex]

where

A = 4πd² and L ∝ R²T⁴

[tex]F = \dfrac{R^2T^4}{4 \pi d^2} \\ \\ F \alpha \dfrac{R^2T^4}{ d^2} --- (2)[/tex]

Given that:

distance d₁ = 20 pc

Then, using equation (2)

[tex]F_1 \ \alpha \ \dfrac{R^2_1T^4_1}{ d^2_1}[/tex]

However, we are also being told that there is a temp. drop by a factor of 3;

So, the final temp. [tex]T_2 = \dfrac{T_1}{3}[/tex]; and the final radius is [tex]R_2 = 100R_1[/tex] since there is increment by 100 folds.

Now;

[tex]F_2 \ \alpha \ \dfrac{R^2_2T^4_2}{ d^2_2}[/tex]

SInce;

[tex]F_1 = F_2[/tex]

It implies that:

[tex]\dfrac{R^2_1T^4_1}{ d^2_1 } = \dfrac{R^2_2T^4_2}{ d^2_2} \\ \\ d_2 = \sqrt{\dfrac{R_2^2T_2^4}{R_1^2T_1^4}}(d_1)[/tex]

Replacing all our values, we have:

[tex]d_2 = \sqrt{\dfrac{(100R_1)^2 \times (\dfrac{T_1}{3})^4}{R_1^2T_1^4}}(20 ) \\ \\ d_2 = \sqrt{\dfrac{(100)^2 }{3^4}}(20 ) \\ \\ d_2 = \sqrt{\dfrac{(100)^2 }{3^4}}(20 ) \\ \\ d_2 =222 \ pc[/tex]

Answer:

Explanation:

1. a as pitch depends on frequency

2. b as loudness depends on intensity

3. d as that is definition of frequency

4. c as that is definition of timbre

5. c as sonar can do both

6. d as that is definition of infrasound

7. d

8. b as that is one of three bones in the middle ear

9. c as you hit the drum to make sound

10. d

11. ultrasound

12. acoustics

13. ultrasound

14.  harmonics? or resonance?

15. noise

16. b

17. b

18. b

19. a

20. b

Answer:

angular velocity = 2.6543 rad/s

Explanation:

To find the angular velocity of the wheel when the disk moves to the right 0.5 ft, we need to be aware that the spring will stretch twice the value of gyration with any slight change in the position or movement of gyration since the top of the wheel is holding the spring.

The work done here:

= ((distance moved by the wheel) X spring constant X (Final displacement^2 - Initial displacement^2)) + Mass (q2 – q1)

Where q2 = 0.5ft

            q1 = 0.8 lb      

Note that linear velocity = radius X angular velocity

= -0.5(10)(1^2 – 0) + 15(0.5/0.8) = 4.375 ft·lb    

Then, the kinetic energy :

 Since the spring is initially unstretched, the initial tension in the spring = 0

So the final tension = ((distance moved by the wheel) X (linear velocity)^2 X (angular velocity) ^2 + (distance moved by the wheel) X (linear velocity) X ( radius of gyration) ^2 X (angular velocity) ^2

= 0.5(40/32.2)(0.8w) ^2 + 0.5(40/32.2)(0.6)^2 X w2

final tension = 0.621 w2

So the angular velocity of the wheel when disk moves to the right 0.5 ft = The Initial workdone + Initial kinetic energy will be equal to the final workdone + the final Kinetic energy

0 + 4.375 ft·lb = 0.621 w2

 angular velocity = 2.6543 rad/s

Answer:

The pressure before expansion is 717.1 kPa.

Explanation:

We need to use the Ideal Gas equation to find the initial pressure:

[tex] PV = nRT [/tex]

Where:

P: is the pressure

V: is the volume

n: is the number of moles

R: is the gas constant

T: is the temperature

Since the number of moles does not change after the expansion, we need the following number of moles:

[tex] n = \frac{P_{f}V_{f}}{RT_{f}} [/tex]  (1)

Where "f" is for final

Before the expansion, the pressure is:

[tex] P_{i} = \frac{nRT_{i}}{V_{i}} [/tex]   (2)

By entering equation (1) into (2) we have:

[tex] P_{i} = (\frac{P_{f}V_{f}}{RT_{f}})(\frac{RT_{i}}{V_{i}}) [/tex]

[tex]P_{i} = \frac{P_{f}V_{f}T_{i}}{T_{f}V_{i}} = \frac{900 kPa*900 cm^{3}*292.15 K}{550 K*600 cm^{3}} = 717.1 kPa[/tex]

Therefore, the pressure before expansion is 717.1 kPa.                  

I hope it helps you!        

Answer:

air

Explanation:

water is a liquid and can be refracted.

glass is a solid which can also be refracted.

however,

air you can't see just see mainly.

air is the answer.

hope this helps :)

Answer:

4.8 turns would be made around the tube

Explanation:

You need the circumference of the tube since it's just a lifted circle

2×pi×3=18.85

90.42/18.85=4.79

And round that to 4.8

Answer:

it is d, just did the quiz. all this came from the amazing com mentor who said a was wrong and it is d, thank you.

Explanation:

This splitting of the big atomic nucleus into smaller nuclei is known as nuclear fission, and further discussion is as follows:

The neutron collides with a uranium atom that splits during the fission of nuclear, producing a tremendous quantity of energy in the form of heat produced. If a uranium atom splits, additional neutrons are extricated.

Therefore, the final answer is "Option D".

Find out more about the nuclear fission here:

brainly.com/question/913303

Answer:

Friendships can have a major impact on your health and well-being, but it's not always easy to build or maintain friendships. Understand the importance of friendships in your life and what you can do to develop and nurture friendships