Measuring the force needed to overcome friction for a wooden block

Equipment

wooden block with affixed curtain hook and mass hanger
4 x 100 g masses
500 g top pan balance
0-10 N newton meter
board pen

Method

1. Zero the newton meter by turning the adjustment screw.
2. Use the top pan balance to measure the mass of the wooden block. Note down the mass.
3. On the desk draw around the wooden block to ensure the block starts from the same place each time.
4. Place the block in the rectangle on the desk.
5. Attach the newton meter to the curtain hook.
6. Very slowly increase the force used to pull the newton meter away from the block.
7. Note the force at which the block first slips across the desk.
8. Repeat steps 4-7 a further two times and calculate the average force required to make the block slip.
9. Add a 100 g mass to the wooden block. Write down the new mass of the block.
10. Repeat steps 4-8 for this new mass of the block. Keep adding masses and repeating until you have five rows of data.

Note:

• to convert a mass in kg to a weight in N multiply by 10
• to convert a mass in g to a weight in N divide by 100.

Risk assessment

hazard	risk	probability	mitigation
heavy equipment	crush injuries	low	keep equipment in centre of desk

There are no other significant risks.

Images

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