Friction Apparatus

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This set includes a friction block and a friction board, both made of smoothly finished pine wood. The friction block has a hook for spring scale and two compartments for additional weights. 
It can be placed face-up or sideways. Students can vary the weight or area of contact to see their impact on the friction force. 
Comes with three 50 g weights and a 100 g spring scale. 
Size of board: 20 in. x 2 in. Size of block: 4 in. x 1-1/2 in. x 1 in.