Page 588 - SUBSEC October 2017_Neat

PRACTICAL ACTIVITIES (cont’d)

(ii) Your experimental value for your eye level is, therefore, X + s. Express this in term of heights.
(Remember you have already found X from (A). Example: Suppose s = 1.4. If each section in
your experimental sheet was 1.5 cm wide, then s = 1.4 implies 1.4 X 1.5=2.1 cm.

Your experimental value for your eye level is X in cm + s in cm.

C. Repeat the experiment by standing at a longer distance (½ to 2 times your previous throwing
distance) away from the board. You may have to use more sheets firmly fastened together so
that all your throws land on the sheets. You may also have to divide your sheets into more
sections of approximately 2 cm to cover all your points.

Plot a histogram of the new results and calculate X + s in cm again.

Comment on your results.

STATIONARY WAVES

Refer to Unit 1, Module 2, Specific Objective 2.9

Aims: (a) To investigate the properties of stationary waves.
(b) To measure the wavelength and frequency of microwaves.
(c) To estimate the velocity of sound in free air.

Method:

A. Stationary waves on a string

To signal generator

vibrator

load

Turn on the signal generator and find the frequency required to produce a one-loop standing wave.
Then find other frequencies which give 2 loops, 3 loops …………..

By means of a linear graph use your results to find the velocity of the waves on the string.

CXC A16/U2/17 88