Centripetal Force Lab Questions?

[master x964]

So we did a lab in physics today and it was a contraption where we had a stopper on one get of the string, and weights on the other, and we spun the stopper around, and there's 4 questions that i don't under stand, so if you could help me with this, and please explain as i want to know how to do this, that'd be awesome!

Questions:

1. In an experiment using this apparatus the mass and centripetal force are kept constant, by how much must the velocity change to increase the radius a factor of four(4X)?




2. You calculated the acceleration of the stopper for both lengths. What factors determine the acceleration and rank the factors from greatest to least.


3. Suppose you find that a centripetal force of 12 Newtons is required to keep a given object in a particular circular path when it is moving with uniform speed. Assume you are able to double the mass, velocity, or radius individually at will.
a) What will the magnitude of the centripetal force be for each of these individual changes?



b) Which change modifies the centripetal force the most and why?


4) Write the equation for centripetal force in terms of: mass, revolutions, radius, and period (using any constants needed).
a) What effect would an error in time measurement have on the F in time was too large?
b) What effect on the calculated F would a radius have if the value used for radius was too small?

 

[Greg Bernhardt]

You need to show some evidence that you tried to work through these questions. Tell us what you know, the relevant information and where you are getting stuck.

 

[master x964]

ok here's my answers they probably AREN'T Correct so please don't base yours off of mine
1. 8 times

2.

3a.

3b. The mass, and the velocity, the higher the mass the more higher of velocity you need to maintain the speed

4. F(of centripetal force) = m4(pi^2)rf^2

and I'm working on 2 and 3a ... still