3. Riddle:
I am black when you buy me, red when you use me and grey when you throw me away.
What am I?

Answers

Answer 1

Answer:

The answer is charcoal

Answer 2

Answer:

Charcoal

Explanation:


Related Questions

Question 6 of 10
What is the role of the commutator in a DC generator?
O A. It causes the magnetic fields of the permanent magnets to
reverse.
B. It causes the electric current to constantly reverse its direction.
C. It keeps the electric current flowing in one direction.
D. It keeps the magnetic fields of the permanent magnet steady.
SUBMI

Answers

Answer:

C. It keeps the electric current flowing in one direction.

Explanation:

just got it correct on my quiz.

The commutator in a DC generator keeps the electric current flowing in one direction option (C) is correct.

What is a DC generator?

A direct current generator's principal job is to transform mechanical energy into electricity. Internal combustion engines, water, gas, steam turbines, and even hand cranks are all sources of mechanical energy for DC generators.

The commutator in a DC generator converts the alternate current into the direct current.

Thus, the commutator in a DC generator keeps the electric current flowing in one direction option (C) is correct.

Learn more about the DC generator here:

https://brainly.com/question/17144871

#SPJ2

A cyclist acceleration from 0m/s to 8m/s in 3second. what is his acceleration?​

Answers

Answer:

2.66 m/s² .

Explanation:

Initial velocity , u = 0 m/s

Final Velocity , v = 8 m/s

Time Taken , t = 3 s

So , Acceleration = (v-u)/t = (8 m/s - 0 m/s) /3 sec . = 8/3 m/s² = 2.66 m/s²

What year was the RoboSapien toy robot released?
a) 2007
b) 2004
c) 2020
d) dunno

Answers

option b )2004........


A 1 kg puck sliding on a horizontal shuffleboard court is slowed to rest by 1 point
a frictional force of 3 N. What is the coefficient of kinetic friction between
the puck and the surface of the shuffleboard court? *
O A. 0.25
O B.0.5
O c.0.15
D. .31

Answers

Answer:

miu = 0.31

Explanation:

The friction force is defined as the product of the normal force by the coefficient of friction.

[tex]f=miu*N[/tex]

where:

f = friction force = 3 [N]

miu = friction coefficient

N = normal force [N]

The normal force on a horizontal surface can be calculated by means of the product of mass by gravity.

where:

m = mass = 1 [kg]

g = gravity acceleration = 9.81 [m/s²]

[tex]N=m*g\\N=1*9.81[/tex]

[tex]N= 9,81 [N][/tex]

Now replacing in the equation above, we can find the friction coefficient.

[tex]miu=3/9.81\\miu = 0.31[/tex]

what is relative density?

Answers


Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. ... For example, an ice cube, with a relative density of about 0.91, will float. A substance with a relative density greater than 1 will sink.

A pitcher throws a ball toward a player holding a softball bat. The bat applies a 10-Newton force to the ball. Which statement correctly describes the reaction force between the bat and the ball?

Answers

Answer:

The reaction force is the force that causes the ball to move toward the bat.

Explanation:

Answer:

D; the reaction force is the force of the ball on the bat.

Explanation:

A large ball of Play-Doh with a mass of 0.04kg is launched from a catapult with an initial
speed of 5m/s and an
initial height of 1.0m. What is the final speed of the ball right before it strikes the ground? Draw a picture!

Answers

Answer:

  ≈ 6.68 m/s

Explanation:

A suitable formula is ...

  vf^2 -vi^2 = 2ad

where vi and vf are the initial and final velocities, a is the acceleration, and d is the distance covered.

We note that if the initial launch direction is upward, the velocity of the ball when it comes back to its initial position is the same speed, but in the downward direction. Hence the problem is no different than if the ball were initially launched downward.

Then ...

  vf = √(2ad +vi^2) = √(2·9.8 m/s^2·1.0 m+(5 m/s)^2) = √44.6 m/s

  vf ≈ 6.68 m/s

The ball hits the ground with a speed of about 6.68 meters per second.

__

We assume the launch direction is either up or down.

What is the average speed of a race car that moved 20 kilometers in 10 minutes?

Answers

Answer:21

Explanation:every body said

The velocity of a mass moving in a circular path is..

Answers

Constantly changing.

Which of the following is true about particles of matter?

Answers

What are the possible answers

Answer:

Matter is a substance which has mass and takes up space by volume the properties of matter are,

States of matter (solid,liquid,gas)are inter convertable.

Force of attraction varies from one kind of matter to another.

States of matter can be varied by varying temperature and pressure.

Explanation:

An atom of the element chromium has an atomic number of 24 and a mass number of 52. How many electrons are in an uncharged atom of chromium?

0
24
28
52

Answers

Answer:

it's 24

Explanation:

I took the test and got 100 %

Answer:

24

Explanation:

Where is the deepest cave in the world? How far down is it located?
i need help asap please help fast

Answers

Answer:

Geology Notes

1 Veryovkina Cave 2212[1] 13.5 km (8.4 mi)[1] Abkhazia / Georgia 43°23′52″N 40°21′37″E.

what does it mean to say energy is conserved

Answers

This means that energy cannot be destroyed or created. They can be converted to other types of energy but the energy before and after will be constant.

2. (1) A piece of rubber is 50 cm long when a weight of
35 N hangs from it and is 85 cm long when a weight
of 70 N hangs from it. What is the spring constant
of this piece of rubber?​

Answers

Answer

By F = -kx {-ve just indicating the sign of the force}

=>35 = k x (85-50) x 10^-2

=>k = 100 N/m

Again by F = -kx

what is the weight of a 15 kg object

Answers

to get weight multiply Mass by 9.8

weight =9.8x15=147N

Which of these is an appropriate treatment for a deep, bleeding wound?
A. Walk the person around.
B. Remove any embedded object.
C. Elevate the wound.
D. Apply a tourniquet.

Answers

Answer:

Elevate the wound.

Hope this helped!

A marble is given potential energy by being placed by a location w. When the marble is released it rolls down the track at which location dose the marble have maximum kinetic energy w x or y or z

Answers

Answer:

The answer is "Location Y"

Explanation:

Please find the complete question in the attachment.

As we show in the graph when the marble rolling with the full force it will stop on the y location because it is curved, and the marble can't move to another location, that's why the maximum kinetic energy of the marble is at the y location.

who is the prime minister of bangladesh ???

Answers

Answer:

Sheikh Hasina is the prime minister of Bangladesh.

Answer:

her name is Sheikh Hasina

A6 kg bag of rice is on the top shelf at a grocery store.
The height of the shelf is 2 meters.
What is the rice bag's gravitational potential energy?

Answers

Answer:

117.6 J

Explanation:

The gravitational potential energy of a body can be found by using the formula

GPE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 9.8 m/s²

From the question we have

GPE = 6 × 9.8 × 2

We have the final answer as

117.6 J

Hope this helps you

Answer:

b

Explanation:

Rodney hits a 0.060 kg tennis ball straight up with a speed of 15 m/s from a height of 2.2 m above the ground. How fast is the ball going when it is 9.5 m above the ground?

Answers

Answer:

Explanation:

From the question we are told that

   The mass of the tennis ball is  [tex]m = 0.060 \ kg[/tex]

    The speed is  [tex]u = 15 \ m/s[/tex]

    The initial height of the ball is  [tex]h_o = 2.2 \ m[/tex]

     The height considered is  [tex]h = 9.5 \ m[/tex]

Generally the time taken to reach the considered height is mathematically evaluated from the equation of motion as follows

           [tex]h = h_o + ut - \frac{1}{2} gt^2[/tex]

=>         [tex]9.5 = 2.2 + 15t - \frac{1}{2} * 9.8 t^2[/tex]

=>         [tex]7.3 = 15t - 4.9t^2[/tex]

=>          [tex]4.9t^2 -15t + 7.3[/tex]

solving the above equation using quadratic formula

           [tex]t= 0.6070 \ s[/tex] and  [tex]t_1 = 2.454 \ s[/tex]

Generally from kinematic equation we have that

        [tex]v = u - gt[/tex]

=>     [tex]v= 15 - 9.8 * 0.6070[/tex]

=>      [tex]v= 9.0514 \ m/s[/tex]

Note if we had used the second values of time the velocity at 9.5 \ m would have been negative which is not correct given that at maximum height velocity is zero

This equation goes with which law?

Answers

Answer:

I think that's Newton's second law of motion

Explanation:

f = m(v-u)

________

t

since a = (v-u)t

f = ma

which option lists materials in order by their ability to allow the flow of electrons, from most easily to least easily?
A. Conductor, semiconductor, insulator
B. Semiconductor, insulator, conductor
C. Insulator, semiconductor, conductor
D. Semiconductor, conductor, insulator ​

Help me pls!

Answers

Answer: Conductor, semiconductor, insulator

Explanation:

Just did the quiz

The correct option is option A.

The descending order in which electrons flow easily is:

Conductor, semiconductor, insulator

Conductivity and flow of electrons:

The correct order for materials by their ability to allow the flow of electrons, from most easily to least easily is Conductor, semiconductor, insulator.

Conductors are generally metals, they have plenty of free electrons due to which the electron flow is easy. Also, the conduction band and valance band in a conductor overlap, so they can conduct at room temperature.

In the case of semiconductors, the band gap between the conduction band and valance band is almost 1eV, so a little energy is enough to make the flow of electrons possible

Whereas, in insulators, the band gap is quite high and electrons can not jump from the conduction band to the valence band due to which the flow of electrons is not possible.

Learn more about band gap:

https://brainly.com/question/14124478?referrer=searchResults

A football player runs due South for 80 yards then cuts up the field due East for a distance of 45 yards before running into the end zone. What is the total displacement of the player?

Answers

Answer:

91.79 yards

Explanation:

Let the direction of the south be -y

Let the direction of the east be +x

The displacement is gotten by using the pythagoras theorem as shown;

Let d be the displacement;

d² = x² + y²

Given

x = 45 yards

y = -80 yards

Substitute the given values into the expression;

d² = x² + y²

d² = 45² + (-80)²

d² = 2025 + 6400

d² = 8425

d = √8425

d = 91.79 yards

Hence the total displacement of the player is 91.79 yards

As we know, the moon is a satellite of our earth, what is the
theoretical period of the moon? The average radius of the
moon's orbit is 3.84 108 m and the mass of the earth is 5.97 x
1024 kg (in hours, G = 6.67 x 10-9 N (m/kg) 3).

Answers

Answer:c

Explanation:c

This question involves the concepts of the time period, orbital radius, and gravitational constant.

The theoretical period of the moon is "658 hr".

The theoretical time period of the moon around the earth can be found using the following formula:

[tex]\frac{T^2}{R^3}=\frac{4\pi^2}{GM}[/tex]

where,

T = Time Period of Moon = ?

R = Orbital Radius = 3.84 x 10⁸ m

G = Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

M = Mass of Earth = 5.97 x 10²⁴ kg

Therefore,

[tex]\frac{T^2}{(3.84\ x\ 10^8\ m)^3}=\frac{4\pi^2}{(6.67\ x\ 10^{-11}\ N.m^2/kg^2)(5.97\ x\ 10^{24}\ kg)}\\\\T^2=(9.91\ x\ 10^{-14}\ s^2/m^3)(56.62\ x\ 10^{24}\ m^3)\\\\T=\sqrt{561.34\ x\ 10^{10}\ s^2}[/tex]

T = 2.37 x 10⁶ s[tex](\frac{1\ h}{3600\ s})[/tex]

T = 658 hr

Learn more about the orbital time period here:

https://brainly.com/question/14494804?referrer=searchResults

The attached picture shows the derivation of the formula for orbital speed.

Matt is driving his car around a curve that has a radius of 40 m. If his speed is 25 m/s as he negotiates the curve, find the centripetal acceleration for the curve.
A- 13.9 m/s2
B- 24.6 m/s2
C- 15.6 m/s2
D- 7.25 m/s2

Answers

Answer:

[tex]\huge\boxed{\sf a_{c} = 15.6\ m/s^2}[/tex]

Explanation:

Given Data:

Radius = r = 40 m

Speed = v = 25 m/s

Required:

Centripetal Acceleration = [tex]\sf a_{c}[/tex] = ?

Formula:

[tex]\sf a_{c} = \frac{v^2 }{r}[/tex]

Solution:

[tex]\sf a_{c} = \frac{v^2}{r} \\\\a_{c} = \frac{(25)^2}{40} \\\\a_{c} = \frac{625}{40} \\\\a_{c} = 15.6 m/s^2\\\\\rule[225]{225}{2}[/tex]

Hope this helped!

~AH1807

A parallel-plate capacitor is constructed using adielectric material whose dielectric constant is 3.00 and whose dielectric strength is 2.00X108V/m. The desired capacitance is 0.250 μF, and the capacitor must withstand a maximum potential difference of 4.00 kV. Find the minimum area of the capacitor plates.

Answers

Answer:

A = 0.188 m²

Explanation:

First we find the distance between the plates by using the formula of electric field intensity:

E = ΔV/d

d = ΔV/E

where,

d = distance between plates = ?

ΔV = Potential Difference = 4 KV = 4000 V

E = Electric Field = 2 x 10⁸ V/m

Therefore,

d = 4000 V/(2 x 10⁸ V/m)

d = 2 x 10⁻⁵ m

Now, we find the Area of Plates by using formula of capacitance:

C = A∈₀∈r/d

where,

C = Capacitance = 0.25 μF = 0.25 x 10⁻⁶ F

A = Area of Plates = ?

∈₀ = Permittivity of free space = 8.85 x 10⁻¹² C/N.m²

∈r = Dielectric Constant = 3

Therefore,

0.25 x 10⁻⁶ F = A(8.85 x 10⁻¹² C/N.m²)(3)/(2 x 10⁻⁵ m)

A = (0.25 x 10⁻⁶ F)(2 x 10⁻⁵ m)/(3)(8.85 x 10⁻¹² C/N.m²)

A = 0.188 m²

Typically, a bullet leaves a standard 45-caliber pistol (5.0-in. barrel) at a speed of 262 m/s. If it takes
1 ms to traverse the barrel, determine the average acceleration experienced by the 16.2-3 bullet withim
the gun and then compute the average force exerted on it.

Answers

U should use the website called acceleration calculator soup it helps a lot for physics

Calculate the average speed of a runner who runs for 500 meters in 40 second HELP!

Answers

Answer:

12.5

Explanation:

500 divided by 40 = 12.5

The temperature of a substance is 45 C. Convert this to Kelvin.

Answers

Answer:

it will be 318.5 Kelvin


A beaver runs at a speed of 2.0m/s with 45 J of kinetic energy.

What is the beaver's mass?
Round answer to two significant digits.

Answers

Answer:

22.5 kg

Explanation:

solve for mass in the kinetic energy equation then round to a whole number

A beaver runs at a speed of 2.0 m/s with 45 J of kinetic energy.

What is the beaver’s mass?

Answer: 22.5 kg

Other Questions
A transverse and longitudinal wave combine to form what kind of wave?a sound wavea radio wavean electromagentic wavea surface wave how many valence electrons does Ne have Student #2:4x + 1 -4x + 1 -1x -2Solved the inequality incorrectly but graphed their solution correctly.Solved the inequality incorrectly and graphed their solution incorrectly.Solved the inequality correctly and graphed their solution correctly.Solved the inequality correctly but graphed their solution incorrectly. Find the lengths of all 3 sides of each triangle. Which of the following is NOT characteristic of special districts? A. They have rights to buy and sell property B. They are intergovernmental units created for specific purposes. C. They handle services or responsibilities that the state or local government could not fulfill . D. They are privately-owned companies that are paid by the government to provide specific services What idea is the poster trying to convey? What is seen in the middle of March and April that cant be seen at the beginning or end of either month? PLEASE I HAVE 5 MINUTES 10. In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxeswere sliding toward each other and crashed. The crash caused both boxes to change speed. Basedon the information in the diagram, which statement is correct? In your answer, explain what theforces were like and why the boxes changed speed (5pts)Box 1 has more mass than Box 2.Box 1 and Box 2 are the same mass.Box 1 has less mass than Box 2. HELP PLS ASAP!!!!!!! fill in the blanks human beings continue to grow Till the age of dash God spoke to Abraham through the burning bush. True False Former Prime Minister of the United Kingdom Margaret Thatcher stated that, "Ronald Reagan won the Cold War without firing a shot." She meant thatPresident Reagan used nuclear weapons instead of guns to win the Cold War.Reagan used economics to win the Cold War instead of military mightthe President used a policy of brinksmanship instead of dtente to win the Cold War.None of these choices are correct List 3 values that wouldmake this inequality true.er.C 4 + g 29 Can someone pls help me!!! Help this confusing no matter how any times I do it Need helpIn what way does the protagonists point of view reflect his cultural background?A. The protagonist is disappointed by the decay he observes as a commonplace problem throughout Russian societyB. The protagonist is surprised when he meets someone who does not conform to his beliefs about socialhierarchy.C. The protagonist begrudgingly exchanges niceties with the old non in order to follow the norms of RussianhospitalityD. The protagonist wishes to challenge societal expectations of businessmen, focusing on his affairs despitethe obstacles he faces. The team not only won the championship, ____________. Select one: but they also broke the record for most goals in one game. but they are breaking records for most goals in one game. records were breaking for most goals in one game. breaking records for most goals in one game. We want to find the zeros of this polynomial:p(2) = (2x - 1)(x+3)(x + 1)(x - 2)Plot all the zeros (x-intercepts) of the polynomial in the interactive graph. Proteins are chains of amino acids bonded together. Which is the correct sequence for making proteins? Dead rows focus on which muscle region of the body? abdominal back chest calves