Posts: 12,677
Threads: 77
Likes Received: 3 in 3 posts
Likes Given: 0
Joined: Dec 2014
(06-28-2023, 08:15 AM)tommymck_imp Wrote: (06-28-2023, 07:55 AM)GoldOxide_imp Wrote: People, already posted - inertial storage.
Think: Freight train stoppage.
There is a whole lotta friction during the best of times without asserting the brakes. Look how long they take to stop these not-so-light long bricks-in-the-wind even with ALL brakes asserted (a very long distance).
Well, yes in that case....but if you had a "bike" with skinny hard wheels and you disconnected the chain, and you towed it up to 40 mph, it would potentially go as far or farther than a car if you reduced friction enough. The main point is it's the relative ratio of friction and mass. A hockey puck on ice may travel farther than a car coasting on ice given the same starting speed (see...I brought it down to a level that you Canadians can grok
)
Heh, heh, ... grok, ... I think I understand now.
Posts: 2,998
Threads: 118
Likes Received: 654 in 281 posts
Likes Given: 669
Joined: Apr 2025
My boat is '17...my friends is '20...same width. His out weighs mine by 2000lbs. Given the same speed, it takes a lot longer for his to come to a stop than it does mine. That's why he always gets upset with me when when I drive his boat and he wants to ski. He'll be in the water after a fall or get-off, waiting for me to come around. I keep nearly running him over when I drive his boat because it takes longer to stop. Usually I hit reverse in time.
Posts: 474
Threads: 33
Likes Received: 0 in 0 posts
Likes Given: 0
Joined: Feb 2018
(06-28-2023, 12:58 PM)m in sc_imp Wrote: having have slid a braked car along an iced road for an unusually long distance with the brakes locked i'd have to disagree.
I still think the car 'wins'.
mass will be a greater factor than coefficient of friction between the 2 examples.
5000 lbs car on 4 tires has less c.f. per "lbs" than a 1? lb puck with its full side dragging on the ice.
Coast, not brake. Coefficient of static friction is less than coefficient of kinetic friction and if the tires are flatish and there is other losses typical of a coasting car, the puck will go farther. Regardless, the point is that if you lower the deceleration of the lighter object by enough to overcome the mass difference, it'll go farther. It's just a question of the ratio of F/M. In the extreme, add a passenger in a car, repeat the experiment using the same (now heavier) car with brakes applied and it'll come to a stop faster even though the car has less mass. It's a question of degree.
Posts: 111
Threads: 29
Likes Received: 0 in 0 posts
Likes Given: 0
Joined: Mar 2021
The same reason it's easier to lift a load with 4 pulleys than it is with two?
Posts: 387
Threads: 43
Likes Received: 1 in 1 posts
Likes Given: 0
Joined: Jul 2022
Okay my friends, shall we give up on this? Physics is clearly not our strength.
Posts: 12,677
Threads: 77
Likes Received: 3 in 3 posts
Likes Given: 0
Joined: Dec 2014
... herein this thread lies the answer, The Gecko.
Posts: 1,360
Threads: 10
Likes Received: 123 in 71 posts
Likes Given: 316
Joined: Apr 2025
(06-30-2023, 04:23 AM)The Gecko_imp Wrote: Okay my friends, shall we give up on this? Physics is clearly not our strength.