About this item:
This set includes a friction block and a friction board, both made of high-quality, smoothly-finished pine wood. 
The friction block has a hook for a spring scale and three compartments for additional weights. It can be placed face-up or sideways. 
Students can vary the weight or area of contact to test their impact on the frictional force. The set comes with three 50g weights and a 100g spring scale. The board is 20" x 2" and the block is 4" x 1.5" x 1". Includes an activity guide.
 
Shipping weight: 1.1 Lbs., Dimensions: 20" x 2.25" x 2".