B Inclined treadmills and Galilean Invariance

  • B
  • Thread starter Thread starter A.T.
  • Start date Start date
A.T.
Science Advisor
Messages
12,914
Reaction score
3,962
TL;DR Summary
A Steve Mould video about inclined treadmills and Galilean Invariance:
This has been discussed many times on PF, and will likely come up again, so the video might come handy.



Previous threads:

 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Let there be a person in a not yet optimally designed sled at h meters in height. Let this sled free fall but user can steer by tilting their body weight in the sled or by optimal sled shape design point it in some horizontal direction where it is wanted to go - in any horizontal direction but once picked fixed. How to calculate horizontal distance d achievable as function of height h. Thus what is f(h) = d. Put another way, imagine a helicopter rises to a height h, but then shuts off all...

Similar threads

Replies
131
Views
14K
Replies
7
Views
1K
Replies
9
Views
5K
Replies
46
Views
10K
Replies
53
Views
6K
Replies
1
Views
1K
Replies
3
Views
553
Back
Top