WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709

1998 WAEC Physics Practical     You are provided with a uniform metre rule, a knife edge and a...

Physics
WAEC 1998

 

Open photo

 

You are provided with a uniform metre rule, a knife edge and a body m of mass 50g. Suspend the given body m by means of a thread from 1.0cm mark of the metre rule. Balance the loaded metre rule on the knife-edge as shown in the diagram above. Determine and record the value of x when the metre rule is in horizontal equilibrium. Evaluate \(\frac{1}{x}\). Repeat the experiment for values of m = 70, 90, 110, 130 and 150g respectively. In each case, determine and record the corresponding values of x and \(\frac{1}{x}\). Tabulate your readings. Plot a graph of m on the vertical axis and \(\frac{1}{x}\) on the horizontal axis, starting both axes from the origin (0,0). Determine the slope s, of the graph and the value of m for which /\(\frac{1}{x}\) = 0. State two precautions taken to ensure accurate results.

(b)i. Using your graph, determine the value of x for which m = 0.

(ii) State two conditions necessary to maintain the metre rule in the experiment above, in equilibrium.

(iii) Using your graph, determine the value of x for which m = 100g.

WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
Explanation

Table of values/Observation

S/N m(g) x(cm) (cm)
1 50.00 49.75 0.0202
2 70.00 39.65 0.0252
3 90.00 35.10 0.0285
4 110.00 30.75 0.0325
5 130.00 27.40 0.0365
6 150.00 25.00 0.0400

Open photo

Slope (s) = \(\frac{\bigtriangleup {m(g)}}{\bigtriangleup {\frac {1}{x}(cm^{-1})}}\) = \(\frac{130-10}{0.04-0.0145}\)

\(\frac{140}{0.0255}\) = 4705.88(g cm)

Deduction: When \(\frac{1}{x}\) = 0, m = \(\frac{1}{x}\)66.00g

Precaution:

- l avoided draught by switching off the fans.

- I ensure that the suspended mass did not touch the table.

- I avoided error due to parallax when reading the metre rule

- Zero error of the metre rule was noted.

(b)i. From the graph, when m = 0, \(\frac{1}{x}\) = 0.0125

\(\therefore\) \(\frac{1}{x} = \frac{1}{0.0125}\) = 80 cm

(1) Sum of upward forces = sum of downward forces.

(2) Algebraic sum of all the moments about the pivot is Zero.

ii. when m = 100g. X = 0.0305

\(\therefore\) \(\frac{1}{x} = \frac{1}{0.0305}\) = 32.97cm


Report an Error Ask A Question Download App
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
WAEC offline past questions - with all answers and explanations in one app - Download for free

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
WAEC offline past questions - with all answers and explanations in one app - Download for free