In this lab, the students had to propel their standard cars with rubber bands. Each group manipulated rubber bands in the following ways:

* Stretch the rubber band across to the opposite axle.

* Wind the rubber band in opposite directions.

* Attach the rubber band under, the over the axle.

Some of the students’ observations are listed below:

* The more we wound the rubber band,  the faster and farther it went.

* When we stretched the rubber band across to the opposite axle, we increased the potential energy. Then, when we released the rubber band, it had more kinetic energy.

* Number of times you wrap the band+  the tighter you wrap the rubber band, + resistance = speed of the car.

*By winding the rubber band backwards, it would spin the axle backwards propelling the car backwards.

For this lab, the students needed to use their knowledge of what made their vehicle move fast and slow from their last lesson to design a fast-moving car of their own.

What made our vehicle move slow:

• Heavy Load
• No Slope
• String got stuck
• Not enough washers

What made our vechile move quickly:

• Less Load
• Clear Path
• Correct Design
• More Washers

In today’s lab, the students set up experiments to examine the effect mass has on an object while maintaining a constant force. The students added up to two different wooden blocks to their standard vehicles to investigate the effects of a load on motion. During the lab, the students measured the time it took for a loaded vehicle to move a given distance. They then discussed and graphed their results and observations, which provided a good review of past math concepts: range, median and mode. Two new vocabulary words the students learned were:

 Mass- the amount of material in an object

Weight- the amount of force gravity exerts on an object’s  mass.

 Lesson Summary:

A. What did you observe when testing various loads  (blocks)?

Team F:

* Every time a block was removed, less time was recorded. (Used 13 washers)

Team D:

* With five washers and no blocks, the car went its fastest, staying in a range of 2-4 seconds.

Team A:

* When two blocks and ten washers were moved, we had to tap it a bit to get it to move.

*  On one of the trials, no blocks had the same time as two blocks.

B. How did the vehicle move when it was loaded with two blocks?

Team B:

* We needed to push the vehicle to get it to move.

Team C:

* It took 31 washers to move the car.

C. How did the motion of the vehicle change when you removed one block? How did it change when you removed both blocks?

All groups: The car went faster.

D.  When the vehicle carried no blocks, what was left to influence it’s motion?

Group C: The weight of the vehicle itself.

F. What can you conclude about the effects of load on a vehicle’s motion?

How heavy the car is depends on how fast it is.

Today, the students disassembled their own car designs and built a standard model. Each team of 3-6 students received 16 small weights, a bookend, clips and string. Their goal was to determine the effect adding additional weight would have on speed and distance of their cars.

 Predictions:

* Adding extra weight will slow the car down.

* The extra weight will make the car move faster.

* More weight creates more force- This will cause the car to move a greater distance.

Objective:To represent a side and top view of the vehicle. 

What we learned:

Converting scale is a lot easier than it looks.

  Challenges we faced:      

*Our biggest challenge was drawing and measuring the vehicle and also having to convert the measurements to fit the paper! 

 What we know about motion:

* You need wheels in order to get a vehicle to move.

* Motion depends upon forces (push and pull)

What we know about design:

 * We know that parts have to work together to make a vehicle move.