eLearning Lesson 2 by Choi_Min_Suk (10)

Part 1:

1. This is a picture of one of our cloth hangers. It uses linkages in
the middle for the two stands to rotate, therefore making it flat when
folded.
2. This is a picture of a tap. It uses the machine lever. When the
knob is lifted up, there is a movement of the joints, allowing the
water to flow out.
3. This is a picture of a see-saw. It also use the machine lever. It
is the 1st class lever where the fulcrum, the joint, is in the middle
and the two kids on it are the loads/efforts.

Part 2:

Well, I have a dog at home and somehow it maybe has fleas, but it
always feels itchy. The best place to scratch itself is the 'low' fan
where there are lots of gaps to have its fur scratched. There is
always fur stuck there (its clean now because its washed). The good
part is that its scared of the sound made by the fan, so when it ons,
it runs away. I made this idea to make the fan on when my dog tries to
scratch on it. This uses the lever system. The arrows show the
directions of the metal poles when the bottom platform is pressed. So
when my dog presses on it, the fan turns on and my dog runs away. In
fact this can benefit us as we ourselves can step on the platform to
on the fan.