1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
natta225 [31]
3 years ago
6

Each time you dumped the pennies, one half-life passed; it has been shown that the half-life for this radioactive isotope is 20

years
In the year 2000, an archaeology team unearths pottery and is using this isotope for radiometric dating to place the age of the pottery
It is shown that 95% of the nuclei have decayed
Approximately how long ago was the pottery made?
Physics
1 answer:
tresset_1 [31]3 years ago
3 0
The exponential decay function is shown as:

At = Ao*2^(-t/h)

Where:

At = Final amount
Ao = original amount
t = time
h = years for half-life to occur

We are not given the original and final amounts, but we are told that after the certain amount of time had passed, only 5% had remained. So if we were to isolate At and Ao in one side of the equation, such that: At/Ao = 0.05, we can solve for the missing variable, which is t.

Substituting:

<span>At/Ao = 2^(-t/h)
</span>0.05 = <span>2^(-t/20)
t = 86.44 years

Therefore, the pottery was made approximately 86.44 years ago.</span>
You might be interested in
In a research facility, a person lies on a horizontal platform which floats on a film of air. When the person's heart beats, it
anastassius [24]

Answer: 3.48g

Explanation:

here, we will be using conservation of momentum to solve the problem. i.e the total momentum remains unchanged, unless an external force acts on the system. We'll in thus question, there is no external force acting in the system.

Remember, momentum = mass * velocity, then

mass of blood * velocity of blood = combined mass of subject and pallet * velocity of subject and pallet

Velocity of blood = 56.5cm = 0.565m

mass of blood * 0.565 = 54kg * (0.000063/0.160)

mass of blood * 0.565 = 54 * 0.00039375

mass of blood * 0.565 = 0.001969

mass of blood = 0.00348kg

Thus, the mass of blood that leaves the heart is 3.48g

7 0
3 years ago
Read 2 more answers
A ball of gas becomes a ____ when nuclear fusion begins in its core.
Ira Lisetskai [31]
The answer to this is Protostar.

This is a process where it is gathering mass from its parent molecular cloud. Its a very young star meaning, the star was now born. 

Hope this helped :)
Have a great day
8 0
3 years ago
A proton is 0.9 meters away from a 1.4 C charge. What is the magnitude of the electric force between the proton and the charge
Digiron [165]

Answer:

F = 2.49 x 10⁻⁹ N

Explanation:

The electrostatic force between two charged bodies is given by Colomb's Law:

F = \frac{kq_1q_2}{r^2}\\

where,

F = Electrostatic Force = ?

k = colomb's constant = 9 x 10⁹ N.m²/C²

q₁ = charge on proton = 1.6 x 10⁻¹⁹ C

q₂ = second charge = 1.4 C

r = distace between charges = 0.9 m

Therefore,

F = \frac{(9\ x\ 10^9\ N.m^2/C^2)(1.6\ x\ 10^{-19}\ C)(1.4\ C)}{(0.9\ m)^2}

<u>F = 2.49 x 10⁻⁹ N</u>

8 0
3 years ago
Read 2 more answers
A train of mass 5.6 × 10^5kg is at rest in a station.at time t=0s, a resultant force acts on the train and it starts to accelera
lana66690 [7]

Answer:

420000N

Explanation:

Given parameters:

Mass of the train  = 5.6 x 10⁵kg

Acceleration  = 0.75m/s²

Unknown:

Resultant force = ?

Solution:

According to newton's second law, force is the product of mass and acceleration;

   Force  = mass x acceleration

Resultant force that acts on the train is given below;

 Force  = 5.6 x 10⁵kg  x 0.75m/s²  = 420000N

7 0
3 years ago
The phases of the moon depend on how much of the lighted side of the moon can be seen from Earth.
Ostrovityanka [42]

Answer:

true

Explanation:

if there is no light it's different from when there is

3 0
3 years ago
Other questions:
  • A. Describe the mass, charge, and location of protons, neutrons, and electrons in an atom.
    8·2 answers
  • I have to get this done today 
    8·1 answer
  • Some refrigerators use propane as their energy source. What kind of energy do these refrigerators utilize?
    7·2 answers
  • Many spacecraft have visited Mars over the years. Mars is smaller than the earth and has correspondingly weaker surface gravity.
    12·1 answer
  • The process in which acids and bases react so that the properties of both are lost to form water and a salt is called __________
    6·1 answer
  • When an object absorbs light, what usually happens to its temperature?
    6·1 answer
  • What type of crime is committed when a hacker steals someones's bank accounts information
    8·2 answers
  • The speed of sound in air is approximately 350 m/s. You are sitting in a canyon with cliffs 525 m from you. You clap your hands.
    9·1 answer
  • The distance between two charged objects is doubled. What happens to the electrostatic force between the two?a)It will double.b)
    13·1 answer
  • Which is NOT true about oxygen-17 and oxygen-18?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!