please help, brainest if correct

Answer:

71

Explanation:

Answer:

The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.

Explanation:

Answer: The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.

Answer:

The equivalent resistance of the parallel circuit would be 20 Ω

Explanation:

To calculate the resistance of resistors connected in parallel, the formula to be used is

1/R = 1/R₁ + R₂ + R₃ + R₄...

1/R = 1/120 + 1/60 + 1/40

1/R = (1 + 2 + 3)/120

1/R = 6/120

1/R = 1/20 Ω

This can be rewritten or cross-multiplied to be

R × 1 = 20 × 1

R = 20 Ω

The equivalent resistance (R) would then be 20 Ω

Answer:

a. They are typically operated at lower temperatures.

a. They are typically operated at lower temperatures.b. They are especially helpful for viewing cool or obscured astronomical objects.

Answer:

The answer to this question is given below in this explanation section.

Explanation:

                     " law of conservation of energy"

The law of conservation of energy states that energy can neither be created nor destroyed only converted from one form of energy into another.This mean that a system always has a same account of a energy,unless it is added from the outside.This is particularly confusing in the case of non conversation forces,where energy is converted from ,mechanical energy into thermal energy.but the overall energy does remain the same.The only way to use energy is to transform energy from one form to another.

The amount of energy in any system than it is determined by the following equation.

Ut=Ui +W+Q

It is also possible to determined the change in internal energy of the system using the equation.

ΔU=W+Q

The mechanical energy of a system increases provided their is no loss of energy due to friction.The energy would transform to kinetic energy when the speed is increasing.Te mechanical energy of a system remain constant provided their is no loss of energy due to friction.

The law of conversation of energy which say that in a closed system total energy is conserved that is it constant.

KE1 + PE1=KE2+PE2

The earth receives energy from the sun in one day than all the energy consumed by humans in one year.

The sun provides around 174 petawatts of energy to Earth, of which 89 petawatts is absorbed by the planet.

The Global energy consumption is roughly 15 terawatts annually.

Thus, we can conclude that, the earth receives energy from the sun in one day than all the energy consumed by humans in one year.

Learn more about energy of sun here: https://brainly.com/question/2193109

#SPJ1

Answer:

A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.[1] The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3]

The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features.[4] In many ways, a black hole acts like an ideal black body, as it reflects no light.[5][6] Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe directly.

Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.[7] The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.

Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is consensus that supermassive black holes exist in the centers of most galaxies.

The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by friction, forming quasars, some of the brightest objects in the universe. Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed."[8] If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.

On 11 February 2016, the LIGO Scientific Collaboration and the Virgo collaboration announced the first direct detection of gravitational waves, which also represented the first observation of a black hole merger.[9] As of December 2018, eleven gravitational wave events have been observed that originated from ten merging black holes (along with one binary neutron star merger).[10][11] On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope in 2017 of the supermassive black hole in Messier 87's galactic centre.[12][13][14]

Blackness of space with black marked as center of donut of orange and red gases

The supermassive black hole at the core of supergiant elliptical galaxy Messier 87, with a mass about 7 billion times that of the Sun,[15] as depicted in the first false-colour image in radio waves released by the Event Horizon Telescope (10 April 2019).[16][12][17][18] Visible are the crescent-shaped emission ring and central shadow,[19] which are gravitationally magnified views of the black hole's photon ring and the photon capture zone of its event horizon. The crescent shape arises from the black hole's rotation and relativistic beaming; the shadow is about 2.6 times the diameter of the event horizon.[12]

Schwarzschild black hole

Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background

Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively).[20]

Answer:

C. infrared waves

Explanation:

Microwaves are the electromagnetic waves which would the best to use in an object designed to cook food. Thus, the correct option is D.

Microwave is a form of electromagnetic radiation with the wavelengths ranging from about one meter to about one millimeter which is corresponding to the frequencies in the range between 300 MHz and 300 GHz, respectively.

Microwaves are used for cooking food faster than the conventional ovens and would not make a mess in the process. This reheats food instantly quickly. It is helpful for the health conscious people. Microwaves also ensure that a person will never burn the food again. Microwaves are also very economical and energy efficient.

Therefore, the correct option is D.

Learn more about Microwaves here:

https://brainly.com/question/15708046

#SPJ6

Answer:

Transfer of charge by touching is called conduction.

Answer:

5.6x10^4

Explanation:

use the equation V=kq/d

k is the constant 8.99x10^9

V=(8.99x10^9)q/d

q is the charge, 7.5 micro coulombs, but to get coulombs, multiply by 10^-6

V=(8.99x10^9)(7.5x10^-6)/d

And from the problem, we know that the distance is 1.2 meters

V=(8.99x10^9)(7.5x10^-6)/1.2

This simplifies to 5.6x10^4

The electric potential is 5.6 x 10⁴ v.

To find the electric potential the distance = 1.2 m

Charge q = 7.5 UC

               The amount of work needed to move a unit charge from the known point to some unknown point against the electric field  is said to be electric potential.

Formula of an electric potential is

                                     V = k ( q/r)  volt

                   V - electric potential

                    k - Coulomb constant (8.99x10^9)  

                    q -  charge

                     r- distance of separation

  V = (8.99x10⁹) (q/d)

  q = 7.5 UC ( micro coulomb) 10⁻⁶ C

   V=(8.99x10⁹)(7.5x10⁻⁶)/d

Substituting the values,

    V=(8.99x10⁹)(7.5x10⁻⁶)/1.2

    V = 5.6x10⁴ v

Thus, option A is correct.

Learn more about the electric potential,

https://brainly.com/question/15172925

#SPJ2

Answer:

The body becomes a positive charged body.

Explanation:

Given that two objects are shown below. One is neutral and the other is negative. What do you predict would happen?

According to the law of static electricity, like charges repel each other while unlike charges attract each other.

Since one of the object is neutral and the other one is negative, there will neither attraction nor repulsion between them.

Also, according to Electrostatic induction, the neural body can be charged and becomes positive.

The negative body will attract all the positive charges to its side, and repel all the negative charges to the other side. If the body is touched at the other end, the whole negative charges will be earthed and the body will become a positive body.

Answer:

It's a cause that's the last layer

Answer:

I believe the answer is A

Explanation:

It is not the ring of fire because the ring of fire is the result of tectonic plates moving. It is not the biosphere because biosphere is the regions of the surface.  The convecting mantle is the solid layer of the Earth because the mantle is mostly solid. The atmosphere is a solid plastic layer of the Earth. I hope this helps.

Answer:

198.20 N

Explanation:

Given that,

Mass of a heavy bag, m = 25 kg

The bag is attached to the ceiling until it makes an angle of 36 degrees to the vertical.

We need to find the force must the boxer exert on the bag. The force acting on the bag is given by :

[tex]F=mg\cos\theta\\\\=25\times 9.8\times \cos(36)\\\\=198.20\ N[/tex]

So, the required force is 198.20 N.

Answer:

3040 m

Explanation:

The formula to apply here is ;

d=∅*r  where

d is the diameter of the spot , ?

∅ is angle of divergence in radians, = 0.8 * 10⁻⁵rad

r is distance of Moon from Earth, =380,000 km

Applying the formula as;

d=∅*r

d= {0.8 *10⁻⁵} * 380,000 * 1000

d= 3040 m

Answer:

[tex]\leq 40[/tex]

Explanation:

So if you’re going 40mph, your speedometer may read up to 50.25mph - but it can never read less than 40mph. In order to stay within the law, carmakers calibrate their speedometers to slightly overreport their vehicles' speeds.

Answer:

14.8J

Explanation:

PE=MGH

M=0.21

G=9.8m/s

H= 7.2 m

0.21x7.2x9.8= 14.8176 J

Answer:

B

Explanation:

The force and friction cancel each other.

20N - 20N = 0N acting on the object.

Answer:

If the Sun, with its mass of 1 MSun, were to become a black hole the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass

Answer:

It would be 1/3rd size of a neutron star

Explanation:

the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass.

Answer:

1260ft

Explanation:

Given parameters:

Speed  = 105ft/s

Time  = 12s

Unknown:

Skidding distance of the truck  = ?

Solution:

To solve this problem:

       Distance  = speed x time

Now insert the parameters and solve;

  Distance  = 105 x 12  = 1260ft

Answer:

The answer is 494.9 N

Explanation:

I got this same question, and it worked for me! Hope this helps <3

Answer:

your answer will be the letter B

Answer:

Scientists predict that sea levels could rise up to six-feet by 2100. An increase this large will swallow beaches—impacting public access, beach recreation, and healthy ecosystems. ... With less sand beach-goers will have a completely different recreational experience in the future.

Explanation:

Answer:

Hmmm

Explanation:

Here what I know... If a function gives the position of something as a function of time, the first derivative gives its velocity, and the second derivative gives its acceleration. So, you differentiate position to get velocity, and you differentiate velocity to get acceleration. where t is in seconds and H(t) is in inches.

Does this help?

Given :

An object with a volume of 9 cm³ is completely submerged in the water.

To Find :

How much water is displaced by the object.

Solution :

According to Archimedes' principle, the amount of volume displaced of fluid when an object is fully and partially submerged into that is equal to the volume of the object below the surface of liquid.

Now, it is given that object is fully submerged into water.

Therefore, volume of water displaced by the object is 9 cm³.

Answer:

0

Explanation:

the block is being pulled at a constant velocity meaning it has no acceleration. the rule is fnet=mass x acceleration so if theres no acceleration there is no force net!

A block of mass 2 kg is pulled across a surface with a force of 15 N then the net force acting on the block is 0.

A force is an effect that can alter an object's motion according to physics. A force might cause an object has mass to accelerate when it changes its velocity, for, us when it moves away from rest. An obvious way to describe force is in terms of push or pull. A force is a vector quantity since it has equal magnitude and direction. It is calculated using the newton SI unit (N). Force is denoted by the letter F.

The net force exerted by an object was equal to the speed at which its velocity varies over time, according to Newton's second law in its original formulation.

The block has no acceleration because it is being pushed at a constant speed. If there is no acceleration, there is no force net because the formula is net force =mass × acceleration.

To know more about Force:

https://brainly.com/question/13191643

#SPJ3

Answer:

Acids break down fabrics and can cause burns if the acids are strong.

Explanation:

A protective apron or lab coat is important when working with acids because acids break down fabrics and can cause burns if the acids are strong.

Answer:

C

Explanation:

I got it right

Answer:

Technique of comparing abundance ratio between radioactive isotopes to a reference isotope to determine the age of a material called radioactive dating. It determines the age by having a more abundance of isotopes in the cellular being.