

Chinese Chicken Feeder
NAME_______________________________ PARTNER ______________________ DATE
_______
PURPOSE
To study the nature of centripetal force.
MATERIALS
Chicken feeder toy (Chinese Cultural toy), Weight 100g X 2, stopwatch,
ruler
INTRODUCTION
When an object is moving in a circle there will be a centerdirected
force that causes an object to follow a curved or circular path. This force
is called the centripetal force. This lab is to find out the relationship
of centripetal force, mass, and velocity. The equation which shows the
relationship of centripetal force, mass, and velocity is Fc = mv2/r. Fc
represents the centripetal force, m is the mass of the moving object, and
v is the speed of the mass moving in circular motion, and r is the radius
of the orbit of the object.
PROCEDURE
 Make the length of the string attached on the toy 40cm long.
 Tie a 100g mass on the end of the string. *Tie it firmly so the mass
won't fly away.
 Slowly swirl the toy and try to make it so the mass will move in circular
motion with radius of 40cm.
 When the mass moves in perfect circular motion use a stop watch and
measure the time it took to make 30 revolutions.
 Add another 100g weight on the end of the string.
 Repeat the procedure from 3 and 4.
 Change the length of the string to 20cm long.
 Repeat the procedure 2, 3, and 4.
 Change the length of the string to 60cm long.
 Repeat the procedure 2, 3, and 4.
DATA Data
Mass of the Weight (g) 
Revolutions 
Time (s) 
Radius (cm) 
Speed (m/s) 
Centripetal Force (mv2/r) 
























ANALYSIS / CONCLUSION
 After calculating all of the values in the chart, find the relationship
between the centripetal force, mass of the object, velocity of the motion,
and the length of the radius.
 Draw a graph comparing mass of the weight and radius of the circular
motion.
 Draw a graph comparing speed of the motion and mass of the weight.
