Materials for one cart:
8 steel elbows
1 - 3 ft x 3 ft piece of plywood
2 - 3 ft length of 2 x 4
1 pair of the cheapest roller blade style skates you can find (try the clearance isle at your local sporting good store)
16 bolts/nut sets
soft rope for handles
screwdriver or drill with screwdriver bit
allen wrench to fit the roller blade wheels (frequently is included in the packaging for the skates)
Step 1: Assembling the Base Structure
Use screws that will be flat with the surface so students will not nick themselves on screw heads while riding the cart.
Step 2: Attach the Wheels
Its very important to do this step carefully, and use a T-square to make sure the wheels are perfectly aligned.
Use the right angle brackets to attach the wheels to the cart on the 2 x 4's as shown in the photo.
Step 3: Attach Handles
Now that you have your carts, there are lots of applications for them! The most important thing to do is for students to predict what is going to happen before you try it, and for them to draw the free body diagrams for each situation to explain what happened.
- toss a weight to a student sitting on the cart
- have a student sitting on the cart toss a weight to you
- put weight on one of the carts with a student and have two students put the soles of their feet together and push off of each other
- have a student push off of the wall with the soles of their feet while sitting on the cart
You get the idea!