You are provided with the following:
− Salt solution in a 250ml container
− Two identical cylindrical 100g masses
− A string
− A metre rule
− Knife edge
− Two pieces of thread.
Procedure
 Determine the volume V, of one of the masses by using the apparatus provided. Record the volume, V.
V = ………………………………………… (1mark)
Explain how you have determined the volume, V. (1mark)
 (i) Determine the centre of gravity of the metre rule and record it.
Centre of gravity = ……………………………………..(1mk)
(i) Arrange the apparatus as shown in diagram 1 below show that the metre rule is at equilibrium, starting with X = 100mm.
Diagram 1

Measure and record the length, Y. (1mark)
Y =………………………
ii) Repeat procedure a(i) with the following values of X and fill table 1 below.

b) i) On the grid provided, plot a graph of Y (y-axis) against X. (5marks)
ii) Determine the gradient, N, of the graph. (3marks)
iii) The gradient, N, given by the equations N = F/W, where F is the apparent weight of the mass in the salt solution and W is the actual weight of the mass. Calculate the value F and the upthrust, U.
F =………………….. (1mark)
U = …………………. (2marks)
iv) Hence determine the density, p of the salt solution. (2marks)

You are provided with the following:
− A glass block
− soft board
− a plane paper
− four optical pins
− four paper pins
− a protractor
− a 30cm plastic ruler
Procedure
a) Fix the plane paper on the soft board using the four paper pins .
b) Place the glass block on the plane paper. Let the glass block rest on the paper from the broader face.
c) T race the glass block using a pencil
d) Remove the glass block.
e) Mark a point X on one of the longer side of the traced glass block as shown in figure 2. Point X should be 2cm from edge A.

e) Construct a normal at X to emerge through line DC. Let this normal meet line DC at point M.
f) Mark point N along the emergent normal 5cm from M.
g) Construct the line NP to meet the normal at N at 90^o. Line NP can be about 10cm.
h) Using a protractor, construct an incident ray RX at an angle of incidence = 100. Fix two pins P₁ and P₂ along RX.
i) Replace the glass block to the traced figure.
j) View the path of the incident ray RX through the glass block using the other two pins P₃ and P₄. This can be done by
ensuring that the images of P₁ and P₂ are in a straight line with the pins P₃ and P_4.
k) Remove the glass block and draw the emergent ray through P₃ and P₄‍
l) Measure the distance, d of the emergent ray from point N along line NP as shown in figure 3.

m) Record the corresponding values of d in table 2

n) Repeat the procedure for other values of i. (12marks)
o) Plot a graph of sin²i (y-axis) against d on the grid provided (5marks)
d) Calculate the gradient of the graph. (3marks)