Uniform circular motion mass problem

AI Thread Summary
A mass of 1.5 kg moves in a circle with a radius of 25 cm at a rate of 2 revolutions per second. The tangential velocity is calculated to be 3.14 m/s, with a radial acceleration of 39.4 m/s² directed inward. The required centripetal force for this motion is determined to be 59 N. The calculations involve converting the radius to meters and determining the period of rotation. The discussion highlights the importance of understanding the relationship between velocity, radius, and centripetal force in uniform circular motion.
softball1394
Messages
13
Reaction score
0

Homework Statement


A mass of 1.5 kg moves in a circle of radius 25 cm at 2 rev/s. Calcualte (a) the tangential velocity, (b) the acceleration, (c) the required centripetal force for the motion.
Answers:
A) 3.14 m/s
B) 39.4 m/s^2 radially inward
C) 59 N


Homework Equations


v=2piR/T


The Attempt at a Solution


(for part a)
V = 2 pi 25 / T
but what is T?

then i tried:
F = ma = mv^2/r
v^2=Fm/r
v= (the square root of)Fm/r
but I don't know what F is.
 
Physics news on Phys.org
I think I've got it!

V= 2 pi r / t
V= 2 pi .25 / .5
V=1.57/.5
V=3.14 m/s

r = .25, not 25, because it has to be in meters.
and t = .5 because if it takes 1 second to make 2 revolutions, it must take .5 seconds to make one revolution.

yay (:
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top