The physics says that acceleratation down a slope is independent of mass, so a heavier rider shouldn’t have an advantage based on his weight alone. Yet casual observation seems to indicate otherwise for cycling and probably for skiing as well. What gives?
Yes, we do because we crush those minor variations in the road surface that would cause a lighter rider to bounce : )
.
Physics only says acceleration is independent of mass in vacuum. We don’t live in one. Take a pair of twins and put them in the same aero position and then make one of them 10 pounds heavier. The increase in drag because he’s fatter does not offset the acceleration that added weight will give him on a descent.
You sure about that physic?? seems to me that if i drop a penny off a building at the same time as i drop a brick off the same building, the brick will hit the ground first…no???
You’ve been reading “Road” magazine. about the Red Bull Road Rage haven’t you?
J
A heavier object on an inclined slope will over come friction easier than and lighter one>>>>>faster acceleration downhill
.
You’re definitely not scientific. In a vacuum, with no air resistance to consider, they would hit the ground at the same time.
like that good old feather vs. penny in a vacuum tube trick. They tie every time.
They will hit at the same time unless one has a parachute attached to it. Do a test with whatever you have around you, one thing significantly lighter than the other. I just tried it, everything hits at the same time.
So…it doesn’t make sense to me that a heavier person would go any faster. The olympic commentators were saying that the heavier skiers were going much faster. Maybe dropping vs gliding along the ground is not related.
I am so confused!
I think they were talking about heavier skiers going faster in the lower/flatter sections of the course. Probably attibutable to it taking more energy to slow a larger mass down, so they retain their speed for a longer time in the slower sections. Roll a ping pong ball and then see how easy it is to stop it. Then roll a bowling ball and stop it.
OTOH, a bigger skier has to be stronger to make that mass shift directions and absorb the bumps.
Anybody here old enough to remember watching one of the Apollo astronauts drop a feather and a hammer while on the moon? They both hit the surface at the same time.
As for bike riders, we’re not in a vacuum so the rules are different. Because air resistance generally and the ratio of mass to surface area in particular, has a dramatic affect on the rate of acceleration. The heavier rider has a different ratio of mass to surface area and that is what allows him to accelerate faster. Add this to the fact that the extra mass allows the big guy to decelerate slower as the degree of the slope lessens on the way down and you have receipe for the clydes’ payback for the pain he suffered going up hill.
They will hit at the same time unless one has a parachute attached to it. Do a test with whatever you have around you, one thing significantly lighter than the other. I just tried it, everything hits at the same time.
So…it doesn’t make sense to me that a heavier person would go any faster. The olympic commentators were saying that the heavier skiers were going much faster. Maybe dropping vs gliding along the ground is not related.
I am so confused!
I just dropped a pencil and a piece of paper…Guess which one hit first? Now if a crush the paper into a tight ball and drop it…it hits at about the same time as the pencil. Clearly the ball had less force acting on it than the flat paper (larger surface area.)
The inertia of a heavier mass also cause the force of air resistance to have less effect than on a lighter mass. Think about how long it takes a train to stop versus a car if they are both traveling at the same velocity. This causes the air resistance to have less of a result on the more massive skiers.
I think…UMass/Amherst freshman physics 1993.
Galileo is tumbling in his grave, while Newton pokes his eyes with pointy sticks while they read this thread.
It all depends upon how much ether there is in the objects’ immediate environment.
quote “You’re definitely not scientific. In a vacuum, with no air resistance to consider, they would hit the ground at the same time”
Hay wait a minute…he never mentioned a vacuum???
Riders AND skiers carrying downhill faster than those that are smaller due to a larger angular acceleration vector. Most of the downhill specialists are a bit bigger than the pure slalom guys because they can “carry their speed” better in skiing parlance
In my completely unscientific opinion, its all about friction, whether in the hubs, the road, or the snow. There probably is something about that inertia thing as well. hmmmmm
Galileo is tumbling in his grave, while Newton pokes his eyes with pointy sticks while they read this thread.
LOL 
Now that IS funny (along with our horrible physics education in this country)
Gravity acting on an object equals a force (mass x acceleration). That force has to move the object (mass). A 1 kg object will have a gravitation force = 1kg x 9.8 meters/sec = 1 Newton. Now a 100kg object in the same situation will have a gravitational force of 100 Newtons. However, it takes 100x the force to move the 100kg object at the same acceleration. So in a vacuum they accelerate the same.
Let’s add air resistance. Let’s say these objects are roughly the same size and shape which causes air resistance = 1/2 Newton at a given speed. At that point in time the first object will have a net force acting on it of 1/2N and will accelerate a 4.9 meters/sec. The other object will have a net force on it of 99.5 Newtons and will accelerate at 9.31 m/s.
This is a simplified example but it get’s the point across I think.
You’re right, the Galileo and Newton comment is hilarious. It’s more entertaining to let this thread run…