Unit 2 - Dynamics (16-20%)

Question 1

weight/gravitational force is equal to ____.

Answer 1

mass times gravity

Question 2

what is a contact force?
the contact forces (3 things):

Answer 2

a push or pull involving two objects

tension force (Ft), friction (fk), and normal force (fn)

Question 3

Newton’s First Law

what would F net be if at rest/constant motion?

Answer 3

An object at rest will remain at rest, or an object in motion will stay in motion with constant velocity unless acted upon by a NET EXTERNAL force.

Fnet = 0

Question 4

Newton’s Second Law

Answer 4

The acceleration of an object is directly proportional to the net force acting on it, and inversely proportional to its mass.
a = Fnet / m

Question 5

Newton’s Third Law

Answer 5

to any force there is always an equal but opposing force (equal in magnitude)

Question 6

kinetic friction:
equation for kinetic friction:

Answer 6

a force that occurs when two objects are “rubbing” against each other

kinetic friction = (normal force)(coefficient of friction)

Question 7

static friction:
equation for static friction:

Answer 7

a force that occurs when there is a tendency of “rubbing” (trying to move something but it is still at rest because of the friction)

static friction <= (normal force)(coefficient of friction)

Question 8

mass __, but weight ___.

Answer 8

is constant, changes based on gravitational force

Question 9

intertial mass:

the __ mass, the __ force needed to make it accelerate

Answer 9

the tendency of an object to maintain its state of rest or uniform motion in a straight line (resists changes in motion)

greater, greater

NOT a force BTW