PHY 111
Lesson 6 Problem Set 3
Name __Nicole Jauregui_______________
UCM and Gravity
Section _25902_____
Directions:
Several of the following problems are missing some of the given variable
information. Your instructor will provide the values through email in the “From Your Instructor”
section of the weekly lesson or in a course announcement. Use the values provided by your
instructor to answer all of the questions.
Show all your work
. Make sure to use appropriate
labels and units, and highlight your final answers if they are numerical.
1.
A student connects an object with mass m to a rope with a length r and then rotates the rope
around her head parallel to the ground. The object takes 0.5 seconds to complete one rotation.
a)
What is the object’s speed of rotation? (4 pts)
r= 0.50m
V= ∆d/∆t
d= circumference 2pi(r)
∆d= 2pi*0.50m
∆d= 3.14m
V= 3.14m/0.5s
V= 6.28 m/s
b)
What is the object’s centripetal acceleration? (4 pts)
ac=v^2/r
ac= (6.28m/s)^2/ 0.50m
ac= (39.408m^2/s^2)/0.50m
ac= 78.8 m/s^2
c)
What tension force is required to maintain this motion? (4 pts)
M=0.75kg
ΣF=m*ac
