Velocity / Speed loss by shifting to a larger radius

• drewman13
In summary, if 20 pounds was added to the downstroke for a distance of one foot and was removed immediately after that one foot of distance, the resulting velocity would be increased by 15.7 fps.
drewman13
If there was a free-spinning effective weight of 20 lbs. at a 20" radius rotating at 180 rpm (15.7 fps?) and a force of 20 foot pounds was added, what would be the increase in velocity/speed? (Ignoring friction and wind losses).

How do you "add" a force to an object?

Is this a homework question?
What do you expect?

I am an independent inventor. This is not homework. I already have a degree, it is just not in Engineering. The force I am adding is rotational force or torque. This is a device I am building and I am looking to optimize the design. Ideally I would like to know the "payoff" for the input of energy into the system. The source of the force is not important. It could be as basic as a push from a human being's hand.

drewman13 said:
If there was a free-spinning effective weight of 20 lbs. at a 20" radius rotating at 180 rpm (15.7 fps?) and a force of 20 foot pounds was added, what would be the increase in velocity/speed?
While the force was applied the RPM would continuously accelerate.

Baluncore said:
While the force was applied the RPM would continuously accelerate.
Thanks for the reply... I guess I am not good at stating the problem, sorry for the lack of Engineering savvy...Assume for illustrative purposes that 20 pounds was added to the downstroke for a distance of one foot and was removed immediately after that one foot of distance. What I am, basically, looking for is the effect on one rotation. Specifically, I wish to find out what is the maximum gain in velocity from that one input of 20 foot lbs. for one revolution.

You can calculate the moment of inertia of your object, and the kinetic energy as function of its speed follows from that. You have the initial energy, and you increase this by 20 pounds * 1 foot, so you know the new energy, which you can convert back to angular velocity.

You should consider using SI units, as imperial units are just a huge mess if you want to calculate anything.

drewman13 said:
Assume for illustrative purposes that 20 pounds was added to the downstroke for a distance of one foot and was removed immediately after that one foot of distance.
What is a “downstroke”? Is this a vertical axis or horizontal axis rotation?

Your title “Velocity / Speed loss by shifting to a larger radius.” is incompatible
with your OP question “ … , what would be the increase in velocity/speed? ”.

You are using scientific terms in inapplicable ways. That makes for total confusion.
You need to describe the physical system more completely.

Bandit127
mfb said:
You can calculate the moment of inertia of your object, and the kinetic energy as function of its speed follows from that. You have the initial energy, and you increase this by 20 pounds * 1 foot, so you know the new energy, which you can convert back to angular velocity.

You should consider using SI units, as imperial units are just a huge mess if you want to calculate anything.
Thanks for that. I am sure you are right about SI units. My goal was just to see if I could get a hard number for mps or fps or rpm that resulted from the energy input to the vertical rotation. Assuming 180 rpm of original speed . (I added downstroke to imply vertical rotation). My degree is in Communications, (Graduated with Honors). I am much better with words than numbers, although Baluncore is correct that I made quite a few errors in my statement of the problem, including the OP Question. Currently, I am going through a health condition that reduces my cognitive skills. Originally, I attempted to become an Engineer but I quickly learned I am incapable of doing the math. This is one of the few places I can go with help on my inventions when I get stopped by the math. I, literally, would not have a clue as to do what you suggest, even though it is obviously the way to go. Let me know if you know of anywhere I can get something like this calculated, even if it is for a fee. Just need to keep it reasonable. Thanks.

What is the concept of velocity / speed loss by shifting to a larger radius?

The concept of velocity / speed loss by shifting to a larger radius is based on the principle of conservation of angular momentum. When an object moves in a circular path, it has a constant angular momentum. When the radius of the circular path is increased, the velocity of the object decreases in order to maintain the same angular momentum.

How does the radius affect the velocity of an object?

The radius of a circular path has an inverse relationship with the velocity of an object. As the radius increases, the velocity decreases and vice versa. This is because, for a given angular momentum, a larger radius requires a slower speed to maintain the same angular momentum.

Is there a specific formula for calculating velocity / speed loss by shifting to a larger radius?

Yes, the formula for calculating velocity / speed loss by shifting to a larger radius is v2 = v1 * (r1 / r2), where v1 is the initial velocity, v2 is the final velocity, r1 is the initial radius, and r2 is the final radius. This formula is based on the conservation of angular momentum principle.

Does the mass of the object affect the velocity loss when shifting to a larger radius?

No, the mass of the object does not affect the velocity loss when shifting to a larger radius. This is because the conservation of angular momentum principle applies to all objects, regardless of their mass. However, a heavier object may require more force to maintain the same angular momentum when shifting to a larger radius.

Can velocity / speed loss by shifting to a larger radius be observed in real-world situations?

Yes, velocity / speed loss by shifting to a larger radius can be observed in various real-world situations, such as when a car takes a turn on a curved road. The car's speed decreases as it takes a wider turn, in order to maintain the same angular momentum. This phenomenon can also be observed in sports, such as ice skating, where the speed of the skater decreases as they shift to a larger radius curve.

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