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### Course: Physics library>Unit 18

Lesson 11: Simple machines explorations

# Wheel

Este vídeo mostra o funcionamento das engrenagens.
PLEASE NOTE: Some of the videos in this section are silent to allow the viewer to make their own observations about what is happening and respond to the questions posted below.
Khan Academy video wrapper
This video has no sound.
1. Which gondola has the greater mechanical advantage when the one on the left is moved closer to  the axle of the "wheel"? Why?
2. Where is the out side edge of the "wheel" for the gondola on the left after it is moved?
3.  Why do the straight LEGO pieces attached to the gear point at different angles when the gondola on the left is moved?

## Want to join the conversation?

• These are my thoughts, please confirm and correct:

Q1. More force is required to move the left gondola, therefore it has a mechanical advantage, because by applying a lesser force to the right gondola, a greater force is applied on the left.

Q2. 'Where is the out side edge of the "wheel"', no idea what this means.

Q3. They move so that the force applied to the wheels by the weight of the gondolas is balanced on either side (similar to a lever with the fulcrum not centered, and even weights on either side of the lever).
(6 votes)
• Please comfirm and correct:
1)The gondola on the right has a greater mechanical advantage since the input energy is bigger than the output energy
2)The outside edge is between the new axle and the part attached to it.
3)Is it because the left gondola is closer to the wheel?
(4 votes)
• how can a jack wheel lift a car
(1 vote)
• Physically, the center of gravity for a car is right in the middle, but the jack has strong suspenders/ leverage that is can lift a car off the ground, moving the center of gravity not too much, but still sustainable to not break down, so you can lift the car! (Well, maybe only 1 side, but ok).
(6 votes)
• in the second question, what do they mean about the 'outside edge of the wheel'?
(2 votes)
• I don't understand fully what the point of this simple machine involving wheels is for. What is a practical use of this machine in real life?
(1 vote)
• Probably too late, but the simple machine is the wheel itself, not the thing they made with wheels. Wheels have tons of uses. You move faster over a greater distance by riding a bike as opposed to running.
(1 vote)
• How does can a jack wheel support a cars weight
(1 vote)
• How can a jack lift a car?
(1 vote)
• Depends on the type of jack used but this is not related to the topic of the video.
(1 vote)
• why is that the second wheel is not moving faster
(1 vote)
• That's because it's attached to the same axle as the first one.
(0 votes)
• What would have happened if say one was straight down, and the other was put in the exact opposite direction, so straight up. Would the wheels turn them so they then were in a horizontal position, directly across from one another?
(0 votes)
• where is the piviot, fulcrum located
(0 votes)
• since this is a wheel, it doesn't really have a fulcrum. it does have an axle, which is located between the two wheels at the top. the axle is what connects the two wheels and what helps them stay in line and straight. it's also the part that is usually turned to spin the wheels.
(1 vote)