Why won't my mousetrap car move when the trap is set off?

In summary, the mousetrap car needs a gear mechanism to slow the trap spring's release, and a weight to increase the applied force.
  • #1
xdzumux
2
0
I have built a mousetrap car for physics however it will not start. It will only jump in place and then stops. A requirement for the project is that the car must be able to start with a marble is dropped on the trap meaning I am not able to remove ANYTHING from the trap. However when I set off the trap the car only jumps, as I have told you before. BUT when I pull back the snapper arm and set the string normal and DONT set the mousetrap, just letting the car go right afterwards, the car moves about 2 meters. This is a good thing but I NEED the car to be able to move when the trap is set off. Sorry if this is confusing but help please?
 
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  • #2
xdzumux said:
I have built a mousetrap car for physics however it will not start. It will only jump in place and then stops. A requirement for the project is that the car must be able to start with a marble is dropped on the trap meaning I am not able to remove ANYTHING from the trap. However when I set off the trap the car only jumps, as I have told you before. BUT when I pull back the snapper arm and set the string normal and DONT set the mousetrap, just letting the car go right afterwards, the car moves about 2 meters. This is a good thing but I NEED the car to be able to move when the trap is set off. Sorry if this is confusing but help please?
Welcome to PF!.

It sounds to me that you need a gear mechanism so that the trap spring closes more slowly. There is a lot of energy stored in that spring. If you let it out all at once, you cannot harness it to power the car.

AM
 
  • #3
Andrew Mason said:
Welcome to PF!.

It sounds to me that you need a gear mechanism so that the trap spring closes more slowly. There is a lot of energy stored in that spring. If you let it out all at once, you cannot harness it to power the car.

AM

Thank you so much for replying. Do you have any suggestions on what kind of gear mechanisms I could use/create?
 
  • #4
I have seen a mousetrap car fitted with a long wooden arm attached to the mousetrap's moving arm.

The string was attached to the end of this arm and the other end of the string was wrapped around one of the car axles.

This gave power to the car slowly so that it accelerated steadily.

The string has to detach from the axle when acceleration ceases so that the car can run freely. This was done with a small rod at right angles to the axle and attached to it. The string is looped loosely around this.
 
  • #5
While I agree with Andrew that gearing is the proper approach, I feel obliged to mention that coupling the trap arm to a flywheel might achieve the same result with fewer parts.
 
  • #6
Add a two pound weight on top of the car.
 
  • #7
Borek said:
Add a two pound weight on top of the car.

May he borrow your wig for that?
 
  • #8
Won't work, too light.
 
  • #9
Borek said:
Won't work, too light.

Is that with or without the batteries?
 
  • #10
The secret to getting good distance from a mousetrap car is to keep the total weight as low as possible.

Using a light rod to extend the range of movement of the mousetrap arm allows many turns of string around the axle to be pulled off, accelerating the car as it goes.

Flywheels and wigs add too much weight and gears are difficult to implement, so I'd go with the rod.
 
  • #11
I solved the problem as stated, OP never said anything about getting a good distance.
 
  • #12
Yes, you would have to know about that.

In high schools, it is common to set oddball challenges like building bridges out of drinking straws or spaghetti.
Or building the tallest tower out of drinking straws.
Or building a cart powered by a mouse trap or a rubber band. Whose cart goes furthest, wins.
It may just be for fun or it may count as marks like an exam, so it can get very serious.
 
  • #13
A long lever attached to the arm extends the time over which the force can accelerate the car. One can also use large diameter wheels and a pulley on the axle to further increase the application time. The jump is due to the downwards force of the snapper hitting the car upon closure. Most of the energy is transferred to the body when it slams into it. The wheels just spins to quickly for the car to move in this case.
 

1. Why is my mousetrap car not moving at all?

There could be several reasons for this. First, check to make sure that all the components of your mousetrap car, such as the wheels and axles, are correctly attached and functioning. Also, check to see if the mousetrap itself is set up correctly and tightly wound. If all the parts are in working order, there may be too much friction between the car and the surface it is on. Try lubricating the wheels and axles or using a smoother surface.

2. How can I make my mousetrap car move faster?

There are a few ways to increase the speed of your mousetrap car. First, make sure that the wheels and axles are as light and smooth as possible. You can also try using a stronger and more tightly wound mousetrap. Additionally, reducing friction by lubricating the wheels and axles or using a smoother surface can also help increase speed.

3. Why does my mousetrap car only move a short distance before stopping?

This could be due to a lack of tension in the mousetrap. Make sure that the mousetrap is tightly wound before releasing it. If the car still only moves a short distance, check for any obstructions or excess friction that may be slowing it down. It is also possible that the car is too heavy for the strength of the mousetrap. Consider reducing the weight of the car or using a stronger mousetrap.

4. Can I use other materials besides a mousetrap to power my car?

Yes, there are many alternative power sources that can be used for a mousetrap car, such as a rubber band, a balloon, or a CO2 cartridge. Experiment with different materials to see which one works best for your design.

5. How can I improve the design of my mousetrap car?

There are many ways to improve the design of your mousetrap car. Consider making the car more aerodynamic by reducing its weight and adding streamlined features. You can also experiment with different types of wheels and axles to reduce friction. Additionally, try using a longer mousetrap or adding multiple mousetraps to increase the power and speed of your car.

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