Forces Ch. 6. Milbank High School. Sec 6.1 Force and Motion. Objectives Define a force and differentiate between contact forces and long-range forces Recognize the significance of Newton’s second law of motion and use it to solve motion problems
Milbank High School
Agent: a specific, identifiable, immediate cause of a force
Draw a picture of your book sitting on the desk. Identify all the forces acting on it.
What forces are acting on a
skier as she races down a hill?
d & f
f and d
Fg = mg
Kinetic Friction Force
Ff ,kinetic = µkFn
Static Friction Force
0< Ff, static < µsFN
Surface µs µk
Rubber on concrete 0.80 0.65
Rubber on wet concrete 0.60 0.40
Wood on wood 0.50 0.20
Steel on steel (dry) 0.78 0.58
Steet on steel (with oil) 0.15 0.06
Teflon on steel 0.04 0.04
5 m/s w/ chute
The Amplitude is the displacement.
The Frequencyis the number of cycles/sec.
The Period is the time for one cycle T = 1/f