Physics 9702/35 — October/November 2018

You have been provided with a spring.

• Measure and record the length $x_0$ of the unstretched coiled section of the spring, as shown in Fig. 1.1.

$x_0$ = ______

• Set up the apparatus as shown in Fig. 1.2.

The protractor should be attached to the wooden block using some of the Blu-Tack.
The height of the rod of the clamp above the bench should be approximately $35\text{ cm}$.
One loop of the spring should be around the rod of the clamp.
The other loop of the spring should be around the rod of stand B close to the top of the rod and secured using Blu-Tack.

• Slide the base of stand B until the angle between the rod of stand B and the stretched spring is $90^\circ$.
• The length of the coiled section of the spring is $x$.
  The angle between the rod of stand B and the horizontal is $\theta$.
  Measure and record $x$ and $\theta$.

$x$ = ______
$\theta$ = ______

• Calculate $e$ where

$e$ = ______

Change the height of the boss. Slide the base of stand B until the angle between the rod of stand B and the stretched spring is again $90^\circ$.
Measure and record $x$ and $\theta$. Repeat until you have six sets of values.

Record your results in a table. Include values of $e$, $\frac{e}{\cos \theta}$ and $\tan \theta$ in your table.

It is suggested that the quantities $e$ and $\theta$ are related by the equation

where $N$ and $M$ are constants.

Using your answers in (d)(iii), determine the values of $N$ and $M$.
Give appropriate units.

$N$ = ______
$M$ = ______