Y E A R 8 – F O R C E S

FRICTION

AIM & HYPOTHESIS

• AIM: To measure the force of friction between different surfaces.

• HYPTHESIS: Write your hypothesis here.

EQUIPMENT

• large block of hardwood with a hook

• a 5-newton spring balance

• desk• carpet• silk• lino• sandpaper

RISK ASSESSMENT

Risk Injury Prevention

Fill out a risk assessment for your experiment

METHOD

1. Hook the spring balance on to the block of wood.

2. Use the spring balance to pull the block slowly over the desk.

3. Measure the force in Newtons needed to keep the block moving at a constant slow speed. This force is equal to the opposing frictional force.

METHOD

4. Record this reading in your data table.

5. Repeat the measurement 3 times.

6. Repeat steps 1-4 on different surfaces.

RESULTS

Surface Friction needed to move (Newtons)

Trail 1 Trial 2 Trial 3 Average

desk

carpet

silk

lino

sandpaper

DISCUSSION

1. Why was it necessary to take three measurements each time, instead of just one?

2. Which surface produced the most friction?

3. Which produced the least?

4. Why do some surfaces have greater friction then others?

CONCLUSION

Write your conclusion here.