EXAM GUIDELINE GRADE 12 2014

Posted: February 15, 2014 in Uncategorized

Newton’s laws and application of Newton’s laws
(This section must be read in conjunction with the CAPS, p. 62–66.)
Different kinds of forces: weight, normal force, frictional force, applied force (push, pull), tension (strings or cables)
• Define normal force, N, as the force or the component of a force which a surface exerts on an object with which it is in contact, and which is perpendicular to the surface.
• Define frictional force, f, as the force that opposes the motion of an object and which acts parallel to the surface.
Define static frictional force, fs, as the force that opposes the tendency of motion of a stationary object relative to a surface.
Define kinetic frictional force, fk, as the force that opposes the motion of a moving object relative to a surface.
Know that a frictional force:
o Is proportional to the normal force
o Is independent of the area of contact
o Is independent of the velocity of motion
• Solve problems using fmaxs = μsN where fmaxs is the maximum static frictional force and μs is the coefficient of static friction.
NOTE:
o If a force, F, applied to a body parallel to the surface does not cause the object to move, F is equal in magnitude to the static frictional force.
o The static frictional force is a maximum (fmaxs) just before the object starts to move across the surface.
o If the applied force exceeds fmaxs, a resultant/net force accelerates the object.
• Solve problems using fk = μkN, where fk is the kinetic frictional force and μk the coefficient of kinetic friction.

Comments
  1. CT MAIMELA says:

    Download a full document of Physical Science Exam guideline 2014 on dowloads

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s