Name ___________________________________

Build a Double Pan Balance

1. Build a double pan balance as shown using the equipment provided.2. Adjust the bulldog clip so that the metre rule is horizontal.3. Place the 50 g mass in one of the cups4. Add sand to the other cup until the ruler is horizontal.5. Use an electronic balance to check the accuracy of your balance. (Make sure

that you take the mass of the cup into account!)

Mass of sand according to my scale ________________ g

Mass of sand according to electronic scales ________________ g

Difference ________________ g

My scales are accurate to ± …………………..%

This is a(n) excellent / good / reasonable / poor level of accuracy

Extension: Check the accuracy of a 50g mass using the same method.

Is accurate to ± 1% / ± 5% / ± 10% / ± 15% / ± 20% ?

plastic cup

metre rulebulldog clip

steel rod held in retort stand

string