Student Name: Annie Burns
Access Code (located on the underside of the lid of your lab kit): AC-8PYXXK
Lab Report Format Expectations
Utilize college level grammar and formatting when answering text based questions.
Report all equations in a proper mathematical format, with the correct signs and symbols.
Submissions with incomplete or improperly formatted responses may be rejected.
Pre-Lab Questions
1. State the inverse square law in your own words.
The inverse square law tells us that the farther we get away from a source of force, the weaker
the force becomes.
2. State the equation used to find the average velocity of an object traveling in uniform circular
motion.
Vavg = 2Pie(r) / T
3. Consider an object in orbit around the earth, such as a man made spacecraft or the moon. Are
these objects accelerating?
Yes, it maintains a constant speed but it is still accelerating because the direction of motion is
changing.
, Lab 5 Circular Motion & Gravity PHY250L
EXPERIMENT 1: BALANCING CENTRIPETAL FORCE
Introduction Questions
1. Suppose an object rotates 15 times every 2 seconds. State the equation for the period of an
object in circular motion in variable form, then calculate the period of rotation, ensuring you
include the correct units. You must show your work for credit.
T = 1/F
F= 15/2 = 7.5
T= 1/7.5 = .1333 seconds
2. In this lab, you will be rotating a mass on one side of a string that is balanced by a second mass
on the other end of the string (Figure 5). If you apply Newton's Second Law of Motion to mass 1,
m1, and mass 2, m2, you can solve for the period of mass 1, which is
P=
√ π2 r
g
Below, derive this equation by using Newton’s Second Law. You must show all pertinent algebra
and mathematical steps for credit. Hint: assume m1= 4m2. How is the centripetal force on m1
related to the force of gravity on m2?
F= Ma
Ac = V^2/r
Fc = m1 * ac = m1 * V^2/r
Fg = m2 * g
Fc = Fg
4m2 * V²/R = M₂ * g
4 m2* V² = m2 * g * r
V² = (g *r) / 4
V = 2(3.14)r/P
(2(3.14)r/p)^2 = g * r / 4
4(3.14)^2 r^2/ P^2 = g*r / 4
P^2 = 4 * 4(3.14) ^2 r^2/ g*r
P = 2(3.14) sqrt r /sqrt g