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If an alpha particle (Z = 2) of kinetic energy 7 MeV is incident on a gold nucleus (Z = 79), what is its closest distance of approach?

In Rutherford Scattering, an incident particle will reach the closest distance of approach when it is on a collision course head on with the target nucleus. At the closest distance of approach, the alpha par...
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Answered by Robert N. • Physics tutor
5250 Views

When is the subjunctive mood used in French?

At A-level, students will be expected to be able to confidently use the subjunctive mood. With a student, I would first discuss with them what the already know about the subjunctive, or any phrases they alre...
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Answered by Laura S. • French tutor
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Prove that ∑(1/(r^2 -1)) from r=2 to r=n is equal to (3n^2-n-2)/(4n(n+1)) for all natural numbers n>=2.

To prove the above statement we will be using proof by induction as this is the easiest way to prove that the statement holds for all natural numbers n>=2. Firstly, when proving by induction there are thr...
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There are 10 boys and 20 girls in a class. The mean mark in a test for all the class is 60. The mean mark for the girls is 54. Work out the mean mark for the boys.

First let us consider how we calculate the mean test mark in the first place, we add up the individual test marks of the entire class to give the total test mark then we divide by the number of students. Thi...
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Answered by Adam D. • Maths tutor
68142 Views

Give a definition/explanation for the term 'phenotype'

A phenotype is the expression of the genetic constitution of an organism and how it interacts with the environment.
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Answered by Frankie S. • Biology tutor
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