HELP ASAP
this is for science, and if i get the questions right, I pass, but the teacher never taught us the lesson, idrk y. so i really need help:( Im giving away 20 points so please give me your best answers ;)


1. As an astronaut travels from the surface of Earth to a position that is four times as far away from the center of Earth, based on the Law of Gravity which of the following statement is true?


a. mass remains the same and the gravitational pull from Earth decreases

b. weight remains the same and the gravitational pull from Earth changes

c. weight increases and the gravitational pull from Earth stays the same

d. mass decreases and the gravitational pull from Earth increases

2. A satellite is sent into orbit around the Earth, In which of the following situation would the gravitational force be the greatest?


A. 1200 lb satellite orbiting 150 miles above Earth’s surface

b. 850 lb satellite orbiting 150 miles above Earth’s surface

c. 850 lb satellite orbiting 1500 miles above Earth’s surface

d. 1200 lb satellite orbiting 1500 miles above Earth’s surface


3. High and low tides are the regular pattern of rising and sinking ocean-water levels. They are caused when the sun’s gravity and the moon’s gravity pull on ocean water. The moon’s gravity has a greater effect on Earth’s oceans than the sun’s gravity. Why would the moon have a greater effect than the sun?


a. The moon has less mass than the sun.

b. The moon is closer to Earth than the sun.

c. The moon is not as hot as the sun.

d. The moon has less mass than Earth.



4. Which statement about the universality of gravity is false?


a. The gravitational force between two objects depends only on their masses.

b. Any two objects that have mass also have a force of gravity acting between them, no matter how far apart they are.

c. The gravitational force between two objects increases if the objects move closer together.

d. The gravitational force between two objects increases if mass is added to one object.

Answer:

Focal length, f = 10 cm

Explanation:

We have,

A concave mirror forms a real image at 15.0 cm from the mirror surface along the principal axis, it means that the image distance is 15 cm

The object is placed at a distance of 30 cm, u = -30 cm

It is required to find the focal length of the mirror. Let it is f. Using mirror's formula to find it:

[tex]\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}\\\\\dfrac{1}{15}-\dfrac{1}{(-30)}=\dfrac{1}{f}\\\\f=10\ cm[/tex]

So, the focal length of the mirror is 10 cm.

Answer:

hot water

Explanation:

Answer:

a

Explanation:

Answer:

A

Explanation:

all the work is in the attached file :D

Answer:

The answer would be the first option. This occurs because of the presence of the protons. The positive charge of protons and the negative charge of electrons set the balance of each other and usually the net charge turn out to be zero.

Answer:

A magnetic field does not exert a force on particles traveling parallel to the magnetic field.

Explanation:

This is the PLATO answer.

Answer:

A

Explanation:

circulatoy system and respiratory

Answer:

A

Explanation:

;3

Answer:

I think it's C

Explanation:

Answer: Light energy only travels through empty space absent of mass energy and kinetic energy only travels through a medium full of mass energy. ... Waves don't transfer mass because mass is not the same as a wave. Mass can hold “extra” energy but it is that energy that moves through it as a wave, not the particle itself.

In a wave phenomenon, energy can move from one location to another, yet the particles of matter in the medium return to their fixed position. A wave transports its energy without transporting matter. Waves are seen to move through an ocean or lake; yet the water always returns to its rest position.

Explanation:

Answer: A.

The space contains a magnetic field

Explanation:

A charged particle is surrounded by electric field and exerts force on other charges in the field, attracting or repelling them. 

But a charged particles in a magnetic field can escape into infinity without ever stopping due to magnetic force. We can therefore conclude that the space contains a magnetic field

Answer:

Explanation:

B

Answer:

false, each force might have a different about and a different direction

False because each force might have a different about and a different direction.

A force in physics is an effect that has the power to alter an object's motion. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

The vector sum of all the forces equals the net force. In other words, the net force is the sum of all forces, it is obtained by combining all forces as vectors. The net force is the sum of the force vectors A + B + C for the situation of the three forces on the force board.

Work done due to force is given as,

Work done, W = F.S cosФ

Where F is force a vector quantity, S is displacement and Ф is angle between them.

When forces are exerted in different direction than net force is calculated using vector sum.

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Answer:

R =0.672 ohms

Explanation:

We have,

Length of a gold wire is 6 m

Resistivity of gold is [tex]5.6\times 10^{-8}\ \Omega-m[/tex]

Area of cross section of the wire is [tex]5\times 10^{-7}\ m^2[/tex]

The resistance of a wire is given by the relation as follows :

[tex]R=\rho\dfrac{l}{A}\\\\R=5.6\times 10^{-8}\times \dfrac{6}{5\times 10^{-7}}\\\\R=0.672\ \Omega[/tex]

So, the resistance of the gold wire is 0.672 ohms.

Answer:

C

What is the answer please help her

Answer: F = 5.76x10^-1 N

Explanation:

The force between two charges is:

F = k*q1*q2/r^2

where k = 9x10^9 N*m^2/C^2 is the Coulomb's constant.

q1 and q2 = 6x10^-6 C

and r is the distance between the charges, here r = 0.75m

then the force is:

F = ( 9x10^9 N*m^2/C^2)*6x10^-6 C*6x10^-6 C/(0.75m)^2 = 576x10^-3 N

F = 5.76x10^-1 N

We have a positive force, this means that we have a repulsive force.

Answer:

calcium-47

Explanation:

Just did the test. Good Luck!

The isotopes of calcium are artificially produced to use them as a radioactive tracers. Calcium 47 is best suited for use as a radioactive tracers for body's use of calcium.

A radioactive tracer consists of a chemical compound in which one or more atoms are replaced by a radioisotope.

Out of the six isotopes of calcium, calcium 47 is the most suitable isotope.

Calcium-47 consists of the half-life of about five days. This duration is long enough for biological investigations.

Thus, Calcium 47 is best suited for use as a radioactive tracers for body's use of calcium.

Learn more about radioactive tracer.

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Answer:

It does both. Once they get close enough the air does start to get charged, but then they eventually discharge when they touch.

Explanation:

Answer:

1,3,5

Explanation:

i think maybe dont come at me

Answer:

it is 1,3,5

Explanation:

Answer:

It allows the reader to feel more connected to her purpose

Explanation:

If Cooper is using personal examples for her argument, she is allowing the reader see more of her point of view, which can also lead them to feel connected to her purpose

Answer: A.

As a diver rises, the pressure on their body decreases which allows the volume of the gas to decrease.

Explanation:

The problem is that a diver, experiences an increased pressure of water compresses nitrogen and more of it dissolves into the body. Just as there is a natural nitrogen saturation point at the surface, there are saturation points under water. Those depend on the depth, the type of body tissue involved, and also how long a diver is exposed to the extra pressure. The deeper a diver go, the more nitrogen the body absorbs.

The problem is getting rid of the nitrogen once you ascend again. As the pressure diminishes, nitrogen starts dissolving out of the tissues of the diver's body, a process called "off-gassing." That results in tiny nitrogen bubbles that then get carried to the lungs and breathed out. However, if there is too much nitrogen and/or it is released too quickly, small bubbles can combine to form larger bubbles, and those can do damage to the body, anything from minor discomforts all the way to major problems and even death.

6.

Answer:

45 meters

Explanation:

notice that is you multiply the time with the speed the units cancel to get distance.

therefore

distance=velocity(time)

distance=(3)15

distance =45 meters

7.

Answer:

1. the speed is constant

2. the average speed is .5 m/s

Explanation:

I have attached a graph of the data in excel.

from excel i got the equation of the line to be y=.5x with y being distance and x being time.

the function is a position function so if you take the derivative of it you get the velocity which is .5.

since the derivative is a constant the the speed does not change and the average velocity is the derivative.

For constructive interference the path difference must be an integer number of wavelengths. The lowest frequency for this would be the longest wavelength with the path difference equal to one wavelength.

Path length difference(m) = 5.20 - 3.50 = 1.70m.

λ =2m ⇒ f = v/λ

λ/2 =1.70

λ = 3.40m

Taking speed of sound as v = 340m/s:

f = v/λ = 340/3.40 = 100Hz.

"When two waves of identical wavelength are in phase, they form a new wave with an amplitude equal to the sum of their individual amplitudes."

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Answer:114

Explanation:

for Acellus

Answer:

x is positive y is negative

Explanation:

because the ones from x are moving away from it and the ones from are moving towards it

Answer:

x pos y neg

Explanation:

yes

Answer:

6 V

Explanation:

By ohm's law :

V = IR

V = 0.2 × 30 = 6 V

Answer:

V=6V

Explanation:

Use the equation I=V/R and solve for V then use V=IR plug in the numbers.

V=IR

V=30(0.2)

V=6V

Answer:

Nonrenewable

Explanation:

Coal, petroleum, natural gas, propane, and uranium are examples of nonrenewable energy sources.

Energy sources are forms of potential energy that can be used to perform work.

A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed. It is a finite resource. Fossil fuels such as oil, natural gas, and coal are examples of nonrenewable resources.

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The Answer is true, the saying opposites attract are true for magnets when poles match though they repel.

Answer:

true

Explanation:

Answer:

I think the answer is C

Explanation:

Its heavy but not too heavy

Answer:

Explanation:

Oxygen and carbon dioxide