Alternative A

 

Question 1

 

 

 

1. You are provided with a stopwatch, a meter rule, a split cork, retort stand and clamp, a pendulum bob, a piece of thread and other necessary apparatus.
   1. Place the retort stand on a laboratory stool. Clamp the split cork.
   2. Suspend the pendulum bob from the split cork such that the point of support P of the bob is at a height H = 100 cm above the floor Q. The bob should not touch the floor and H should be kept constant throughout the experiment.
   3. Adjust the length of the thread such that the centre A of the bob is at a height y = AQ = 20 cm from the floor.
   4. Displace the bob such that it oscillates in a horizontal plane.
   5. Take the time t for 20 complete oscillations.
   6. Determine the period T of oscillation and evaluate T².
   7. Repeat the procedure for four other values of y =30 cm, 40 cm, 50 cm and 60 cm. In each case, determine T and T².
   8. Tabulate the results.
   9. Plot a graph of T² n the vertical axis and y on the horizontal axis, starting both axes from the origin (0, 0).
   10. Determine the slope, s, of the graph and the intercept c on the vertical axis.
   11. If in this experiment, SR = c, calculate R.
   12. State two precautions taken to ensure accurate results.
2. 1. The bob of a simple pendulum is displaced a small distance from the equilibrium position and then released to perform simple harmonic motion.
      Identify where its:
      1. kinetic energy is maximum;
      2. acceleration is maximum.
   2. An object of weight 120 N vibrates with a period of 4.0 s when hung from a spring. Calculate the force per unit length of the spring.
      [g = 10 ms^-2, π = 3.142]