Potential energy ( Mechanical in this case ) is energy stored by force. so If you are compressing a spring you are increasing more potential to it by force.

3 0

3 years ago

An experiment with 55 co takes 47.5 hours. at the end of the experiment, 1.90 ng of 55-co remains. if the half-life is 18.0 hour

Andru [333]

Answer:

$\boxed{\text{10.7 ng}}$

Explanation:

Let A₀ = the original amount of ⁵⁵Co .

The amount remaining after one half-life is ½A₀.

After two half-lives, the amount remaining is ½ ×½A₀ = (½)²A₀.

After three half-lives, the amount remaining is ½ ×(½)²A₀ = (½)³A₀.

The general formula for the amount remaining is:

A =A₀(½)ⁿ

where n is the number of half-lives

n = t/t_½

Data:

A = 1.90 ng

t = 45 h

t_½ = 18.0 h

Calculation:

(a) Calculate n

n = 45/18.0 = 2.5

(b) Calculate A

1.90 = A₀ × (½)^2.5

1.90 = A₀ × 0.178

A₀ = 1.90/0.178 = 10.7 ng

The original mass of ⁵⁵Co was $\boxed{\text{10.7 ng}}$ .

7 0

2 years ago

I need help with my science work! It’s due tomorrow!

Greeley [361]

1. related, not
2. how fast molecules vibrate
3. how fast molecules vibrate, the number of molecules
4. higher temperature
5. lower temperature
6. more heat
7. less heat
8. degrees
9. joules
10. expand

1. true
2. false
3. false
4. true
5. false
6. false
7. false
8. true
9. false
10. true

4 0

3 years ago