Answer:
a) C= 1/120
b) P(X>=5) = 0.333
Explanation:
The attached file contains the explanation for the answers
The thickness of aluminium needed to stop the beam electrons, protons and alpha particles at the given dfferent kinetic energies is 1.5 x 10⁻¹⁴ m.
<h3>
Thickness of the aluminum</h3>
The thickness of the aluminum can be determined using from distance of closest approach of the particle.

where;
- Z is the atomic number of aluminium = 13
- e is charge
- r is distance of closest approach = thickness of aluminium
- k is Coulomb's constant = 9 x 10⁹ Nm²/C²
<h3>For 2.5 MeV electrons</h3>

<h3>For 2.5 MeV protons</h3>
Since the magnitude of charge of electron and proton is the same, at equal kinetic energy, the thickness will be same. r = 1.5 x 10⁻¹⁴ m.
<h3>For 10 MeV alpha-particles</h3>
Charge of alpah particle = 2e

Thus, the thickness of aluminium needed to stop the beam electrons, protons and alpha particles at the given dfferent kinetic energies is 1.5 x 10⁻¹⁴ m.
Learn more about closest distance of approach here: brainly.com/question/6426420
Answer You ask your coach
Answer:
sum2 = 0
counter = 0
lst = [65, 78, 21, 33]
while counter < len(lst):
sum2 = sum2 + lst[counter]
counter += 1
Explanation:
The counter variable is initialized to control the while loop and access the numbers in <em>lst</em>
While there are numbers in the <em>lst</em>, loop through <em>lst</em>
Add the numbers in <em>lst</em> to the sum2
Increment <em>counter</em> by 1 after each iteration