# Measuring minbot force

I was curious, how are teams measuring the amount of force their minibot is exerting on the top of the pole?

-Danny

Ours is slowly knocking the top out of our pole, we havenâ€™t measured the force that it exerts when hitting. It sure makes a satisfying thunk as it hits though!

we hung a weight from the dowel rod down the center of the pole with nothing else attaching the top plate to the pole, if the top plate lifts we knew we hit it with enough force.

We are not measuring it directly.

4 Newtons is something like 450 grams of force (or am I wrong yet again?), about a pound.

We have a plunger-type limit switch that requires about 4 N to push it closed, and it does that and more. And just looking at it, it gives a nice thunk when hitting the top plate.

The minibot is moving at roughly 1 meter per second, and weighs maybe 2 kg (probably more), the force to stop it in a few centimeters (I assume the plate moves at competition) is well above 4 N just from an inertia point of view.

Back-of-the-envelope:
F=ma, m=2kg, a=((1m/s)/0.1s)=10m/s^2 (I assume 0.1 sec to stop)
20 kg-m/sec^2 (= 20 N).
If it stops faster, force goes up.

Or do I fail Physics yet again??:rolleyes:

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