Physics

Bellwork:  Grab a white board and we will do these on the boards. 


    1.  A 32 kg box is resting on an inclined plane that has an inclined angle of 30 degrees to the horizontal.
       
                a.  Neglecting friction, find the net force pulling the box down the incline.

                b.  If the coefficient of friction between the box and the surface is .23, what is the                     net force pulling the box down the incline?  The acceleration?
   
                c.  Find the normal force.


    2.  A 300 kg ball is at rest on a horizontal surface.  What is the weight of the ball?  What is the normal     force?

    3.  Ian pushes on Dave with a constant force of 400 N, while Dave pushes with a force of 250 N.  If the     combined mass of the two is 220 kg, what is the net force acting on the "two person system"?  What is     the acceleration of the two?  How far will they move in a time of 10 seconds?

Key Concepts to Study:

Forces:
    -2 types: Contact Forces and Field Forces

    -Unit is Newton, kg m/s2

    -Forces are vectors:  Add them together, use free body diagrams to identify what forces are acting in     which direction.

        ex. Weight=mass x gravity
              Tension
              Normal= weight(flat surface), always perpendicular to surface
              Applied force
              Friction= μ x FN

    -Law's of Motion
        a.  First Law: Law of inertia(depends upon mass)
        b.  Second Law
        c.  Third Law

    -Friction: Two types static and kinetic, static > kinetic

    -Pressure

    -Torque

Key Math Problems
    1.  Newton's Second Law: find acceleration, distance traveled, final velocity, vector addition
    2.  Weight
    3.  Friction
    4.  Inclined Plane
    5.  Tension

As you are solving:

    1.  If you are not sure where to start, begin with a free body diagram.

    2.  Determine where your forces are at, for example: Fg(weight), Normal Force, Applied Force, Friction

Physical Science A

Test over work, power, energy, and simple machines.

When you have finished, please work on the vocabulary for the chapter on waves.  These will be due on friday.  Also, the bind will be checked tomorrow while you are working on the test remediations.