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
adoni [48]
2 years ago
10

The half-life of Co-55 is 175 hours. How much of a 4000 g of Cobalt-55 sample would be left after 525 hours?

Physics
1 answer:
Harrizon [31]2 years ago
5 0

We know that whatever amount we start with, half of it decays and forms atoms of other elements in 175 hours.  So in order to figure out how much is left after 525 hours, we'll need to know how many half-lifes pass in that amount of time.

Well, (525 divided by 175) is exactly 3 half-lifes.  So this will be easy.

-- After 1 half-life . . .

. . . . . 50% decays, 50% is still there.

-- After the 2nd half-life . . .

. . . . . (half of the leftover 50%) = another 25% decays, 25% is left.

-- After the 3rd half-life . . .

. . . . . (half of the leftover 25%) = another 12.5% decays, 12.5% is left.

12.5% of 4,000g = (0.125 x 4,000g) = <em>500 g</em> .

============================================

<u>Another way</u>:

After 1 half-life, 1/2 is left.

After 2 half-lifes, 1/4 is left.

After 3 half-lifes, 1/8 is left.

1/8 of 4,000g = (4,000g/8) = <em>500 g </em>.

You might be interested in
9. When making a circuit, why is gold wiring not used?
daser333 [38]

Answer:

Gold is not used for making electric wires because it is too rare, and too costlier than Copper. Silver and copper are used for making wires. Copper is almost used in electric lines

4 0
3 years ago
As a way of determining the inductance of a coil used in a research project, a student first connects the coil to a 5.62 V batte
Reptile [31]

Answer:

Its inductance L = 166 mH

Explanation:

Since a current, I = 0.698 A is obtained when a voltage , V = 5.62 V is applied, the resistance of the coil is gotten from V = IR

R = V/I = 5.62/0.698 = 8.052 Ω

Since we have a current of I' = 0.36 A (rms) when a voltage of V' = 35.1 V (rms) is applied, the impedance Z of the coil is gotten from

V₀' = I₀'Z where V₀ = maximum voltage = √2V' and I₀ = maximum current = √2I'

Z = V'/I' = √2 × 35.1 V/√2 × 0.36 V = 97.5 Ω

WE now find the reactance X of the coil from

Z² = X² + R²

X = √(Z² - R²)

= √(97.5² - 8.05²)

= √(9506.25 - 64.8025)

= √9441.4475

= 97.17 Ω

Now, the reactance X = 2πfL where f = frequency of generator = 93.1 Hz and L = inductance of coil.

L = X/2πf

= 97.17/2π(93.1 Hz)

= 97.17 Ω/584.965 rad/s

= 0.166 H

= 166 mH

Its inductance L = 166 mH

5 0
3 years ago
The line of latitude that is zero degrees latitude is the
Nuetrik [128]

Answer:

Equator

Explanation:

The equator is the line of latitude that separates the earth into the northern and southern hemisphere.Its magnitude is 0 degrees latitude. The equator and other lines of latitude are parallel to each other. The lines of longitude which is 0 degrees is known as the Greenwich meridian. The longitudinal lines however are not parallel as they converge at the poles.

7 0
2 years ago
Which of the following statements are true? Select all that apply.
beks73 [17]

Answer:

The following options are true based on the properties of electric field;

a) Electric field lines near positive point charges radiate outward.

b) The electric force acting on a point charge is proportional to the magnitude of the point charge.

d) In a uniform electric field, the field lines are straight, parallel, and uniformly spaced.

Explanation:

From option b) From coulomb's law F = Kq1q2r/r2

5 0
3 years ago
A substance has a half-life of 10,000 years and an initial mass of 1,000 grams. How many years will pass before only 250 grams o
solmaris [256]
<h3>♫ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ♫</h3>

➷ After 10,000 years the mass will be:

1,000 / 2 = 500

After 20,000 years the mass will be:

500/2 = 250

As you can see, the correct answer would be A. 20,000 years

<h3><u>✽</u></h3>

➶ Hope This Helps You!

➶ Good Luck (:

➶ Have A Great Day ^-^

↬ ʜᴀɴɴᴀʜ ♡

6 0
3 years ago
Read 2 more answers
Other questions:
  • What is transmitted by all waves
    6·2 answers
  • What three basic components are atoms made of?
    12·1 answer
  • A dog runs with an initial speed if 7.5m/s on a waxed floor. it slides to a stop in 15 seconds. What is the acceleration ​
    6·1 answer
  • An overhang hollow shaft carries a 900 mm diameter pulley, whose centre is 250 mm from the centre of the nearest bearing. The we
    10·1 answer
  • The Sun's surface temperature is closest to _____.
    7·2 answers
  • Name all nfl players
    14·1 answer
  • Seven little spheres of mercury, each with a diameter of 2 mm. When they coalesce to form a single sphere, how big will it be (i
    11·1 answer
  • Please answer this for 15 points
    13·1 answer
  • #1. What, roughly, is the percent uncertainty in
    11·1 answer
  • The moon has a mass of 1×10^22 kg, and the gravitational field strength at a distance r from the planet is 0.001 n/kg. what is t
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!