A student has an 80 g sample of a radioactive material that has a half-life of 20 seconds. How much material will he have left after 60 seconds?

A.
10 g

B.
20 g

C.
40 g

D.
5 g

Answers

Answer 1
The answer is C 40 g

Related Questions

A light wave moves from diamond (n = 2.1) into water (n = 1.83) at an angle of 19°. What angle does it have in water?

Answers

Answer:

  θ  = 0.3736

Explanation:

For this exercise, how light passes through two media separated by a distance, so its movement is governed by the law of refraction.

            n₁ sin  19 = n₂  sint  θ

           

let's use subscript 1 for diamond and sub start 2 for water

            sin θo = n₁ / n₂ sin θ

            sin θ  =[tex]\frac{2.1}{1.83}[/tex] sin 19  0.325                                                                                                                                                                                                                                                                              56

            θ  = 0.3736

The hydraulic tool holder is a type of what? A.port B. clamp C. Press D. Actuator​

Answers

Answer:

A

Explanation:

There can be several
in an ecosystem?

Answers

There can be many species in an ecosystem some consume more energy than others

What effect does this gene mutation have on a person?

Answers

Answer:

Harmful mutations may cause genetic disorders or cancer. A genetic disorder is a disease caused by a mutation in one or a few genes. A human example is cystic fibrosis. A mutation in a single gene causes the body to produce thick, sticky mucus that clogs the lungs and blocks ducts in digestive organs.

Explanation:

Seasons occur because _____. Earth is closer to the sun during the summer Earth's orbit is an ellipse Earth's tilt causes the sun's rays to hit unevenly Earth rotates faster at the poles

Answers

Answer:

Earth's tilt causes the sun's rays to hit unevenly

Explanation:

The Earth orbit or rotate in it's axis or orbital plane. When it's rotate, it tilt from the sun rays Earth's tilt causes the sun's rays to hit the Earth unevenly Earth's axis is tilted about 23 degrees, which causes a variation or differences in the sun's latitude.causing it to vary by 23 degrees north of the equator at the start of northern summer to 23 degrees south of the equator at the start of northern winter. On Earth, that tilt is the primary reason for different seasons.

Force=k((q1q1)/r^2)

The force that one electrically charged object exerts on other charged objects can be calculated using Coulomb's law.
You can see this law here written in equation form. The q's represent the two charges, and the r the distance between
the charges. The constant kis 9109
Using this information, calculate the electric force exerted by a +2 coulomb charge on another +2 coulomb charge,
when the charges are 25 meters apart

A)1.44*10^11
B)5.76*10^11
C)8 Newton’s
D)64 Newton’s

Answers

Answer:

transferred from one object to another. Charged objects can exert forces on other charged ... Electric charge can be measured using the law for the forces between charges

The electric force exerted by the +2 C on another +2 C when at a distance of 25 m is 5.76×10⁷ N

Coulomb's law equation

F = Kq₁q₂ / r²

Where

F is the force of attraction K is the electrical constant q₁ and q₂ are two point charges r is the distance apart

How to determine the force Charge 1 (q₁) = 2 CCharge 2 (q₂) = 2 CElectric constant (K) = 9×10⁹ Nm²/C²Distance apart (r) = 25 mForce (F) =?

F = Kq₁q₂ / r²

F = (9×10⁹ × 2 × 2) / (25)²

F = 36×10⁹ / 625

F = 5.76×10⁷ N

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A student performed an experiment in the lab and discovered that the material used has a PH of 8.54. What is true about this material

a
it is a base
b
it is an acid
c
more information needed to know if the material is acid or base

Answers

Answer: b it’s an acid
I hope this helps
it’s B !!!! good job stay in school ❤️❤️

The wasted energy in processing food is “lost” to ____.
mechanical energy
light energy
chemical energy
heat energy

Answers

The wasted energy in processing food is "lost" to heat energy .

What is heat energy ?

The form of energy which is transferred between objects having different temperature is called heat energy.

How heat energy is lost in food processing ?In food processing heat transfer is an essential part. Baking , boiling , grilling , freezing etc . all activities are done for food processing. In all these processes heat energy is lost.

Thus, we can conclude that heat energy is wasted in the food processing .

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For a photoelectric tube, calculate the voltage which will be just sufficient to stop electrons emitted by the sodium photo-plate reaching the collector plate when light of frequency 6 x 1014Hz is incident on a sodium plate. Addition information: 1 e = 1.6 x 10-19C Plank's Constant, h = 6.64 x 10-34 Work function, Wo, of sodium = 2.2 x 10-19J

Answers

Answer:

1.11 V

Explanation:

Given that the Einstein photoelectric equation states that;

KE = E - Wo

E = energy of incident photon

Wo= work function of the metal

E = hf = 6.64 x 10-34 * 6 x 1014

E = 39.84 * 10^-20 J or 3.98  * 10^-19 J

KE = 3.98  * 10^-19 J - 2.2 x 10-19J

KE = 1.78 *  10^-19J

We convert this value of KE to electron volts

KE = 1.78 *  10^-19J/1.6 x 10-19C

KE = 1.11 eV

Hence; 1.11 V will be just sufficient to stop electrons emitted by the sodium photo-plate reaching the collector plate.

what does the splitting of light into component colours through a prism indicate about the composition of sunlight?

Answers

The splitting of light occurs because of the shape of the prism and the different interactions of the components of the white light with the glass. ... This splits the white light into its component colours before it reemerges from the rain drop so a rainbow is produced.

[tex] \huge\longrightarrow{ \mathfrak{ \underline{ Answer }}}[/tex]

The Sunlight is actually white in colour, but it's a mixture of seven different coloured lights of different wavelengths, and when sunlight is passed through a prism, it splits into its constituent units forming a spectrum when observed on a screen. And this shows that the Sunlight is composed of seven different coloured lights .

____________________________

They are :

Red ( highest wavelength )OrangeYellowGreen Blue Indigo Voilet ( lowest wavelength )

____________________________

[tex]\mathrm{ \#TeeNForeveR}[/tex]

Ann and Jesse’s mom is driving them to school. They are listening to music on an FM radio station. When they ride in the car with their father, they sometimes listen to AM radio. Ann wants to find out the difference between AM and FM radio signals. She finds a diagram in an online search. How do the AM and FM radio waves compare? In your answer, explain how the wavelength affects the frequency of the radio waves.

Answers

Answer:

the difference is that the carrier waves are altered. am waves amplitude (strength) is varied in the signal to get sound information. Fm waves frequency’s are varied based on the carrier signal.

Explanation:

Water drips from a faucet at the rate of 150 drops in 120 seconds. What is the period?

Answers

Answer:

.80

Explanation:

The period of the dripping faucet is 0.8 seconds per drip cycle.

What is the rate?

The rate is a measure of how much something changes over time and is typically expressed as a ratio of two quantities with different units of measurement.

Here,
The period of a dripping faucet is the time it takes for one complete drip cycle. To find the period, we need to divide the total time by the number of drip cycles.

In this case, the faucet drips 150 times in 120 seconds, so the time for one drip cycle is,

120 seconds / 150 drips = 0.8 seconds/drip

Therefore, the period of the dripping faucet is 0.8 seconds per drip cycle.

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To make hot chocolate for you and your friends, you must melt 3.0 kg of snow (0.0°C) and heat it to 70.0°C to make the hot chocolate. Calculate the total amount of heat needed.

Heat of fusion of ice = 3.34 × 10^5 J/kg, Specific Heat of Water = 4180 J/(kg.K)

Answers

Answer: [tex]18.798\times 10^5\ J[/tex]

Explanation:

Given

Mass of snow is [tex]m=3\ kg[/tex]

First snow is converted to water at [tex]0^{\circ}C[/tex] and then it is taken to [tex]70^{\circ}C[/tex]

Heat required to convert the ice into water at [tex]0^{\circ}C[/tex]

[tex]Q_1=3\times 3.34\times 10^5\\Q_1=10.02\times 10^5\ J[/tex]

Heat required to raise temperature from [tex]0^{\circ}C[/tex] to [tex]70^{\circ}C[/tex]

[tex]Q_2=3\times 4180\times (70-0)\\Q_2=8.778\times 10^5\ J[/tex]

Total heat required

[tex]\Rightarrow Q=Q_1+Q_2\\\Rightarrow Q=10.02\times 10^5+8.778\times 10^5\\\Rightarrow Q=18.798\times 10^5\ J[/tex]

A light wave travels through water (n = 1.33) at an angle of 35°. What angle
does it have when it passes from the water into the glass (n = 1.5)?
ne sin(e)
Use the equation o, = sin
M₂
n, sing )

Answers

Answer:

30.6 degrees

Explanation:

A light wave travels through water (n = 1.33) at an angle of 35°. It will have angle of 30.56° when it passes from the water into the glass (n = 1.5).

What is Refractive Index ?

When a light is going from medium 1 to medium 2. The refractive index is defined as a ratio of velocity of light in medium 1 to velocity of light in medium 2. Refractive index is the factor which deals with the amount of bending of light. More refractive index means more it will bend in the medium 2. When it is 1 we can say that light has not been bent.

By Snell's law, Refractive index is given by,

sin (i) ÷ sin (r) = μ₂÷μ₁

where i is the the angle of incidence

r is the angle of refraction

μ₂ & μ₁ are refractive index of medium 2 and 1 resp.

Given,

Refractive index of water μ₁ = 1.33

Refractive index of Glass μ₂ = 1.5]

Angle of incidence i = 35°

Angle of refraction r = ?

Light is going from water to glass, hence by snell's law.

sin (i) ÷ sin (r) = μ₂÷μ₁

sin (35°) ÷ sin (r) = 1.5 ÷ 1.33

0.5735 ÷ sin (r) = 1.12781

sin (r)  = 0.5735 ÷ 1.12781

r = 30.56°

Hence it passes from the water into the glass at angle of 30.56°.

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what would the speed of this wave be?

(a) 5 m/s
(b) 50,000 m/s
(c) 100,000 m/s
(d) 5,000 m/s

Answers

Answer:

c) 100,000 m/s

Explanation:

You need to take the same wave length from the top graph and bottom one, so let's take half a wave length then in the top one that is 0.005, but in the bottom one it's 2000/4 = 500 because they are smaller and there are 4 half waves before you get to 2000, whereas in the top one there is 1 half wave before you get to 0.005 on the graph.

Now use speed = distance / time

speed = 500 / 0.005 = 100 000 m/s

Atmospheric pressure is measured by a device called

Answers

Answer:

barometer

Explanation:

Answer:

barometer

Explanation:

A child on a sled has a combined mass of 97 kg. At the top of a 3.1 meter hill, the sled has a velocity of 8 m/s. Assuming there is no friction, what would the velocity of the child and sled be when they reach the top of a different 1.2 meter hill?

Answers

Answer:

Explanation:

This is an energy conservation problem in that the total energy available to a system s constant trhoughout the whole problem. That is, in equation form:

TE = PE + KE. This is a bit of a problem due to sig figs here, but I will keep with the rules for them all the way up til the end of the problem (I'll tell you when I veer away from the rule and why I did when I get there).

We first need to find the total energy available to the system and then use that value throughout the rest of the problem.

TE = PE + KE where

PE = mgh (mass times gravity times height of the object) and

KE = [tex]\frac{1}{2}mv^2[/tex] (one-half times the mass of the object times the square of the velocity of the object). We solve for PE first, rounding to the correct number of sig figs:

PE = 97(9.8)(3.1) and

PE = 2900 J (2 sig figs here since all the numbers given have 2 sig figs in them). Now for KE

[tex]KE=\frac{1}{2}(97)(8.0)^2[/tex] which, to 2 sig figs (notice I added a .0 to the 8), is

KE = 2200. This means that the total energy available to the sled throughout the whole trip is

TE = 2900 + 2200 so

TE = 5100 J

Now for the second part of the problem, the sled is at a different height so the PE is different, and we are asked to find the velocity at the top of this second hill. The total energy equation then is

5100 = PE + KE. Solving for PE first:

PE = (97)(9.8)(1.2) and, to 2 sig figs:

PE = 82. Now for the KE:

[tex]KE=\frac{1}{2}(97)v^2[/tex]. Plugging all of that into the total energy equation gives us:

[tex]5100=82+\frac{1}{2}(97)v^2[/tex] and isolating the v:

[tex]v=\sqrt{\frac{2(5100-82)}{97} }[/tex] and this is where I veer away from the sig figs. Doing the subtracting first, as we should, means that we would round to the hundreds place. Since the least significant place in the number 82 is the tens place and the least significant place in the 5100 is in the hundreds place, we round to the hundreds place. But I didn't keep to this rule because I'm not sure how adamant your physics teacher is about sig figs. I'll give you the answer that I would expect from my students (the right one) after I give you this one. I just simply subtracted 5100 - 82 and used the answer the calculator gave me which was 5018:

[tex]v=\sqrt{\frac{2(5018)}{97} }[/tex] gives us that the velocity at the top of the 1.2 meter hill is

10.2 m/s.

Doing this the right way, using the rules for sig figs properly:

[tex]v=\sqrt{\frac{2(1500)}{97} }[/tex] gives us, to 2 sig figs,

v = 1.0 × 10¹ m/s

mages formed by concave lenses are

Question 13 options:

virtual, upright , diminished (small)


virtual , magnified (enlarged), inverted


real, inverted, magnified


real, inverted, diminished

Answers

Answer:

so its the first option

Explanation:

Concave lenses create only virtual images. After the rays are refracted, they never converge and so there will be no real images. All concave lens images will be upright, virtual, and diminished, and can be found between the F and the lens

Answer: The correct answer is;

Virtual

Upright

Diminished

Explanation: Hope this answers your question :)

pls somebody help me quick

Answers

Answer:

greater than

Explanation:

A bowling ball is bigger than a golf ball and greater than means bigger.

As part of his special theory of relativity, Einstein saw mass as a form of

Answers

Answer:

Energy

Explanation:

Edge 2021

As part of his special theory of relativity, Einstein saw mass as a form of energy.

What is the theory of relativity?

The theory of relativity as stated by Einstein stated that mass and energy are both interconvertible. This explains why energy is released when mass is lost.

Thus, as part of his special theory of relativity, Einstein saw mass as a form of energy.

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#1- How much Magnesium is consumed in this reaction? *input # only.

#2- How much Magnesium Oxide is produced in this reaction? *input # only.

Answers

Answer:

use the mole concept

Explanation:

the mole to mole ratio

When light is incident on a boundary between two mediums, it often slows
down or speeds up. When it does this, the path the light travels can change.
This is called:
A. diffraction
B. reflection.
c. translocation.
D. refraction

Answers

Answer:

the answer is

D.refraction

Make a list of things you pull at home

Please help ASAP. Its for my sister

Answers

Answer: Chairs, Plants, Food, electronics, etc.

Explanation:

Write two properties electric field lines. Sketch electric field lines for an electric dipole​

Answers

Answer:

Properties of an Electric Field

Field lines never intersect each other. They are perpendicular to the surface charge. The field is strong when the lines are close together, and it is weak when the field lines move apart from each other. The number of field lines is directly proportional to the magnitude of the charge.

Explanation:

A uniform 1.5 T magnetic field points north. If an electron moves perpendicular (90 degrees) with a speed of 2.5x10 ^7 m/s, through this field, what force (magnitude and direction) will act on it?

Answers

Answer:

i think its 470

Explanation:

Which is true for a substance that releases energy? A. The energy release decreases the molecular motion and the kinetic energy of the substance. B. The energy release decreases the molecular motion but increases the kinetic energy of the substance. C. The energy release increases the molecular motion and the kinetic energy of the substance. D. The energy release increases the molecular motion but decreases the kinetic energy of the substance. E. The energy release is used only to change the state of the substance.

Answers

Answer:

Option B

Explanation:

State ohms law and derive the relation between current flowing through a circuit and potential difference across the ends of the conductor.

Answers

Answer:

Voltage = current * resistance

Explanation:

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex] V = IR[/tex]

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

When assessing energy resources, it is helpful to use a measure called EROI, which is ________.
A. energy returned plus energy invested
B. energy returned minus energy invested
C. energy returned divided by energy invested
D. money invested in extraction and processing minus income from sales

Answers

Answer: C. energy returned divided by energy invested.

Explanation:

The Energy Return on Investment (EROI) simply means the ratio of the amount of usable energy that is obtained from a particular resource to the amount of the energy that is being expended in order to produce the net amount of the energy.

When assessing energy resources, it is helpful to use a measure called EROI and this is the energy returned divided by energy invested.

Therefore, the correct option is C

Can someone answer this science question NO LINKS !!!!

Answers

pendulum will have greatest potential energy at position 1.

because,at potential energy = mgh and h is greatest at position 1

please mark as brainliest only 1 more brainliest to reach next level

A baseball is thrown at a 22.5° angle and an initial velocity of 65 m/s. What will be its horizontal
and vertical velocity?

Guys pls someone answer my question I have an exam and this question has 5 marks

Answers

Answer:

Horizontal component = 60.05 m/s

vertical component = 22.96 m/s

Explanation:

cosine(angle) = adjacent / hypotenuse or  horizontal / angled velocity

angled velocity * cosine (angle) = horizontal velocity

65 m/s * cosine(22.5) = 60.05 m/s

sine(angle) = adjacent/ hypotenuse or vertical/ angled velocity

angled velocity * sine (angle) = vertical velocity

65m/s sine(22.5) = 22.96 m/s

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