What would happen if the moon's speed
were made to be zero?
D. Centripetal Force (Fc) - force directed toward center of circle which keeps an object moving in a uniform circular path
| Fc = | mac = | mv2 |
| r |
|
Ex) A 5.0 kg object moves in a circle at a constant speed of 10. m/s. What is the radius of the object's circular path if the object's centripetal force is 1000. Newtons? |
Ex) A 5.0 kg object moves in a circle at a constant speed of 10. m/s. What is the radius of the object's circular path if the object's centripetal force is 1000. Newtons?
| Fc = | mv | 2 |
| r |
| 1000. N = | 5.0 kg(10. m/s)2 |
| r |
(1000.) = 500/r
1000r = 500
r = 500/(1000)
r = .50 meters
Image created by John Wetzel, founding author of WikiPremed.
Released under a
Creative Commons Attribution 3.0 License.
E. Changing Centripetal Force
1. Fc & mass?
Put your mouse over each variable above
Direct Relationship
(Both variables on top)
| Mass | Fc |
| x 2 | x 2 |
| x 3 | x 3 |
|
x 4 |
x 4 |
|
x 1/2 |
x 1/2 |
| x 1/4 | x 1/4 |
2. Fc & radius?
Inverse Relationship
(One variable on top,
other on bottom)
| Fc | r |
| x 1/2 |
x 2 |
| x 1/3 |
x 3 |
x 1/4 |
x 4 |
x 2 |
x 1/2 |
x 4 |
x 1/4 |
3. Fc & Velocity?
Direct Square Relationship
(Both variables on top, one is squared)
| V | Fc |
|
x 2 |
x 4 |
| x 3 | x 9 |
|
x 4 |
x 16 |
|
x 1/2 |
x 1/4 |
| x 1/4 | x1/16 |
2 Step Challenge
|
Ex) A toy car moves in a circular track of radius 5.00 m in 10.0 seconds.
|
ac = V2/r
r = 5.00 m
t = 10.0 sec
a = ?
V = d/t
V = (2∏r)/t
| = | [2∏(5.00 m)] |
| (10.0 sec) |
V = 3.14 m/s
ac = V2/r
ac = 1.97 m/s2
Hammer Throw
 |
Satellite Motion |
|