Equipment used

FundamentalApparatus used to measure g Equipment used

Apparatus:

  • Metre rule

  • ball bearing

  • electromagnet

  • electronic timer

  • trapdoor

Apparatus used to measure g

The experiment goes through five stages:

  1. When the current to the magnet switches off, the ball drops and the timer starts

  2. When the ball hits the trapdoor, the timer stops

  3. The reading on the timer indicates the time it takes for the ball to fall a distance, h

  4. This procedure is repeated several times for different values of h, in order to reduce random error

  5. The distance, h, can be measured using a metre rule, in this practical work we use the distances between 20 cm – 1 m

  • Analysing data

  • To find g , use the same steps as in the problem solving section

  • The known quantities are

  • Displacement s = h[1]

  • Time taken = t

  • Initial velocity u = 0

  • Acceleration a = g

  • The equation that links these quantities is

  • s = ut + ½ at2

  • h = ½ gt2

  • Using this equation, deduce g from the gradient of the graph of h against t2