Which items reduce friction and which increase it?For this demonstration, you will need a spring scale. Begin by putting a rubber-band around the length of a wooden block that is at least 3x5x1. Hook the spring scale onto the rubber-band at one end of the block.
Now, pull the wood block across a large Styrofoam tray.
Place marbles in a large jar lid and then put the lid in the Styrofoam tray. Pull the block across the marbles.
Tape a piece of coarse sandpaper, that is as wide as the block and as long as the Styrofoam tray, to the tray. Pull the block across the sandpaper.
Remove the sandpaper and spread oil in the tray. Pull the block through the oik, being careful not to get oil on the scale.
Which setup(s) required the least force to move the wood block? Which required the most?
Anything that reduced the force needed is described as a mechanical advantage.
Drag is a type of friction. Have your student either come up with examples of Higher Friction, Higher Drag, Lower Friction, Lower Drag or have him sort those examples you have typed up for him.
Review Activity: Drag
|Invader, the wooden roller coaster at Busch Gardens, Williamsburg.|
Fixing the Wooden Wonder
This time the roller coaster you need to fix is a wooden roller coaster called the Wooden Wonder. Many roller coaster fans love the wooden coasters even though they don't turn you upside-down and can't be as big as metal coasters. This is because every day the ride on a wooden roller coaster is different depending on the humidity or dryness and the heat or cold.
Last night some teens were caught in the amusement park after closing time. I am afraid that they did something to the Wooden Wonder, and you are shown the ride operate with empty cars. After climbing slowly to the top of the first hill, it plummets to the bottom of the hill, clocking in a speed of 85 mph on the computer sensor read-out. The approved maximum speed for this coaster is 68 mph. When the train returns, you notice that the wheels appear yo have melted a bit. You and the maintenance crew walk along the track and after climbing to the top of the first hill, you all spot something glistening on the downhill tracks. What do you think was found on the track, and why? How can you explain what is happening to the cars, using Newton's First Law of Motion? What can the teens do as their restitution to get the train working as it should?
Work equals force times distance. Have your student use this formula to make up and solve math problems.