2. Target
Todefine
period, frequency, uniform circular
motion, centripetal
acceleration, centripetal force and
centrifugal force;
To
identify the forces acting on a
body moving in a circular path;
3. Target
Toderive the equation for centripetal
force from Newton’s second law of
motion;
Tocite applications of centripetal
force; and
To
solve problems related to circular
motion.
4.
5. Period and Frequency
Period (T) is the Frequency (f) is
time required for the number of
a body to make revolutions
one complete completed by a
revolution. body in a given
time.
Units: s, min, hr. or
Units:
yr. rev/s, rev/min,
rev/hr. or
rev/yr.
6. Uniform Circular Motion
Itis the
motion of a
body that
moves in a
circular path
at constant
speed.
11. Forces
Centripetal Centrifugal
force is the force is the
force that force that is
pulls a body directed
inward when away from
moving in a the center of
circular path. a circular
path.
17. Sample Problem 1
A little girl is playing with her skip ball.
The ball is in uniform circular motion
and makes 20 revolutions in 4 s. (a)
What is its period? (b) What is its
frequency? (c) If the length of the cord
that holds the ball is 0.8 m, what is its
speed? (d) If the ball’s mass is 3
g, how much force is acting on the ball
to keep it in uniform circular motion?
18. Sample Problem 1
Given:
no. of rev = 20
time = 4 s
lengthcord = 0.8
m
mass = 3 g
Find:
a. T c. v
b. f d. Fc
19. Sample Problem 2
A 0.1-kg mass is attached to a
0.9-m length of string. The weight
is swung in a horizontal
circle, making one revolution in
1.2 s. (a) Find the speed of the
mass. (b) What is its centripetal
acceleration? (c) What is the force
that the string exerts on it?
20. Sample Problem 2
Given:
mass = 0.1 kg
lengthstring = 0.9
m
no. of rev = 1
time = 1.2 s
Find:
a. v
b. ac
c. Fc
