Teacher information:

 The concept of this project is that the students will take a common device and use its energy output to propel a vehicle. That common device is a RAT TRAP. Students will be given the opportunity to harness and control a given amount of power that under normal conditions would be released in but a fraction of a second and with great force.

Students will have to form new ideas, explore new concepts and draw on their background knowledge from previous work as they proceed on this project. There are new mechanical factors to deal with which should tax the students' imagination and creativity.

In the "Powered by a Brick" project the students worked with a power source that was for all intents and purposes dead. They could manipulate the brick to do whatever they needed. With the rat trap the power is great and is released right now. The goal is to control this power, get it to the ground and move the vehicle.

As stated the students will have to control the instant power output of a rat trap to propel a vehicle which will have to travel in a straight line for a least fifteen meters. Any method which the students can devise to successfully solve the problem is permissible. With all the development problems there are certain construction and performance parameters that the students projects must meet. They are as follows.

A) Students must build the vehicle, a ready made toy etc. cannot be used.

B) The rat trap may not be cut apart, but may have holes drilled in it, or parts attached to it.

C) Minimum vehicle weight is ___________ grams, Teacher to specify!

  Maximum vehicle weight is ___________ grams.

D) Wheel width must be 150 mm, wheel base must be 420 mm.

E) The vehicle must be able to cover the ten meters in at least eight seconds, and in a straight line.

F) The vehicle must be remotely started from a distance of no less than two meters.

G) The vehicle must start moving under it's own power, and continue unassisted the full ten meters.

 MARKING:

A) Time: ...............20 marks (lose one mark for every second over 10, gain one mark for every 2 second under 10 seconds)

B) Accuracy: ........20 marks (vehicle must straddle centreline, if wheels cross centreline lose one mark for every 10 cm over the line)

C) Weight: ...........20 marks (lose one mark for every 50 grams over or    under the weight range)

D) Size:..................20 marks (lose one mark for every 2 mm over or under size requirements)

E) Construction:20 marks (Teacher's evaluation of the project)

Teachers evaluation of students performance:............100 marks

Total mark = 200

There are certain areas of precaution that should be observed when building the vehicle. The main one being fingers caught in the trap. Caution students before they are given the trap to be mindful that fingers may be hurt if they are caught. Another point of safety to note is that when work is being done on the vehicle the trap must never be in the 'loaded position'.

The majority of the students will elect to power the vehicle through drive axles to wheel and tire assemblies. Some problems that arise will be the overpowering of the tires traction ability, torque steer, and structural failure of the vehicle. Encourage the students to think of unconventional methods of transferring the power to the ground, ie.. four or six wheel drive, track drive, multi gear ratios etc. Information from the Power Mechanics text book on gear ratios, pulley ratios and levers can be discussed as background material prior to the brain storming section of the problem.

  The knowledge learned in the bridge problem will be valuable in the design of the chassis of their vehicle. A reminder of what was learned in the bridge project and its possible application to this problem should allow the students to transfer that knowledge to the rat trap problem. Knowledge transfer is a sought-after goal, and a higher step in the process of critical thinking.

As with any of these projects the role of the teacher should be that of encouraging creative thinking by leading the students to that point of discovery and letting them find the answer, not by telling them. Use all the creative methods you can to allow the students to find out for themselves, only as a last resort tell the answer. Often if the teacher is working on the same project the problem solves itself.

Name: ___________________________
Partner: ____________________________

 Build a vehicle that will be powered by a RAT TRAP. This vehicle must cover a ten meter distance in a straight line in eight seconds, and must be started by remote control from a distance of two meters.

Sound easy? Well here are the construction and performance guidelines for you to follow. 

A) You must build the vehicle yourself, a ready made toy etc. cannot be used.

B) The rat trap may not be cut apart, but may have holes drilled in it, or parts attached to it.

C) Minimum vehicle weight is ___________ grams, Maximum vehicle weight is ___________ grams.

D) Wheel width must be 150 mm, wheel base must be 420 mm.

E) The vehicle must be able to cover the ten meters in at least eight seconds, and in a straight line.

F) The vehicle must be remotely started from a distance of no less than two meters.

G) The vehicle must start moving under it's own power, and continue unassisted the full ten meters.

MARKING

A) Time: ............. 20 marks (lose one mark for every second over 10; gain one mark for every 2 sec. under 10 sec.)

B) Accuracy: ........20 marks (vehicle must stay within the one meter wide track. lose one mark for every wheel outside the line)

C) Weight: ...........20 marks (lose one mark for every 50 grams over or under the weight range)

D) Size:..................20 marks (lose one mark for every 2 mm over or under size requirements)

E) Construction:..20 marks (Teacher's evaluation of your project)

Teacher's evaluation of student's performance:............100 marks