a student is supplied with the following pieces of equipment:
• a small metal ball
• table tennis ball
• metre rule
• stop clock
• calculator
• light gate
• data logger
describe how the student can use this, or other additional equipment, to determine an accurate value for the acceleration of free fall (g). the student need not use all the equipment. show clearly what measurements should be taken and how the students should use these in determining (g). describe one source of error and how this might affect the value of (g).

(6 marks/year9/gcse)

Have the students mark off a vetrtical distance from which to drop the metal ball. Ready the stopwatch, and start when the object is dropped and stop when the object contact the ground. Repeat 5 times and average the stopwatch times.

Now, use the formula d=vo+(1/2)at^2

There's no initial velocity, so d=(1/2)at^2

We know time and distance, so we can solve for a, acceleration.

2d=at^2

(2d)/(t^2)=a

Now, input the numbers gathered in the experiment in meters and seconds.

One source of error is human error (stopwatch timing)

Air resistance (although pretty negligible)