To show that the effect of force depends upon the area of conduct, a student hold both ends of sharpening pencil between the index finger of both the handle and nresses it from both side. the finger which has a deeper mark of a pencil is a) on thumb of both hands
b) towards the flat end of the pencil
c) on firefinger on both their hands
d) towards the pointed end of the pencil

Diagram to question is attached.

a) 56.87°

b) 35.26°

Explanation:

We are given:

a) To find ∅ in air, we use the expression:

Sin∅1 = Sin∅5

Let's substitute figures in the expression above.

We now have:

1.3 Sin40.1 = 1 Sin∅5

= 0.837 = Sin∅5

= Sin∅5 = 0.837

∅5 =

∅ = 56.87°

b) We use the expression:

Sin∅5=n1 Sin1= n2 Sin∅2=n3 Sin∅3=n4 Sin∅4

Since we are to look for ∅4, we have:

n4sin∅4= n_uSin∅5

= 1.45Sin∅4 = 0.837

∅ = 35.26°