(5.3, 5.4) Friction and Gravity
weight: the amount of gravitational pull exerted on an object by the earth
! =

ex. I have a mass of 60. What is my weight (on earth)?
! =
= 60
! = 60 9.80 !
= 9.
Density and Hydrostatic Pressure

Density is a property of all 3 stated of matter
Mass Density mass per unit volume
kg kg
,
o unit:
*note*  1 m 3=1000 L
3
L
m
o Denoted: Dm
m
Dm = mass density
D m=
v
m = mass
V = volume
Ex1: Find the mass density of a 3
September 16th, 2015
Equilibrium
 Equilibrium [statics] is the scenario that includes a system of forces without
a net force
!"# =
= 0
In 2 dimensions: ! = ! = 0 ! = ! = 0
Ex. Find the ten
Acceleration Due to Gravity
 when gravity causes something near thesurface of the earth to fall, the
acceleration of that object is = 9.8/ ! OR 32.2/ ! .
Ex. A rock falls off of a 150m cliff. How long does
September 17th, 2014
The Pendulum
 Periodic motion
 occurs when an object moves repeatedly over the same path in equal time
intervals
ex. Hang a mass from a spring. Pull down on it and release. If there
Speed and Velocity
 speed and velocity tell us how quickly position changes
!"# = Where !"# = average speed
s = distance
t = time
Where !"# = average velocity
!"# =
= displacement
t = tim
5.1, 5.2 Newtons 1st and 2nd Laws
force
 push or pull
 has a magnitude and a direction
 tends to change/prevent an objects motion
 produces acceleration in the direction that force is applied
unit:


October 2nd, 2015
Determining Resultant Forces
Forces are represented as vectors when analyzed
A result in force [also called a net force] is the addition of all the forces acting on
a body and repre
Experiment #3: Nonconcurrent Forces
Purpose: To verify the 2 conditions of equilibrium = 0 and = 0
Procedure:
1. Record the mass of the meter stick below and calculate the weight
using ! = (remember to conve
Forces
Force: A push or pull that tends to cause or prevent motion
 A vector quantity that has both magnitude and direction
 Units of Force are the metric Newton (N) and the imperial Pound
(lb) Note: 4.45N =
Experiment #1:
Kinematics
PHY 168 03
October 1st, 2015
Name: Valarie Benfield
Member Name: Shayna Dalgleish
Member Name: Kara Tessier
Purpose: The purpose of this lab is to calculate the acceleration due to gravity by
observing a ball bearing as it rolls
8.1 8.3 Work, Power and Energy
work the product of force (in the direction of motion) and the
displacement
unit: J (joule), ft lb
 denoted: W
=
W = work
F = force
s = displacement
 ex.
Rotational Dynamics: Torque and Equilibrium Applications
The mass of most rigid bodies can not be isolated or concentrated at one
single point, as was discussed in concurrent systems last chapter.
Objects that have
(5.5 Total Force in 1 Dimension)
 Since force is a vector, we can pick a positive direction and sum them to find total
force.
(
)
Friction: a force opposing the relative motion of 2 objects/surfaces in
5.6 Law of Action and Reaction

ex: when a car accelerates, the ground applies a force on the tires, which is a
reaction to the force that the tires apply onto the ground [action]

Newtons 3rd Law

o For
September 5th, 2014
Calculations Involving Measurements


adding and subtracting
o terms must have same units
o output is only as precise as the least precise input
ex. 25 + 2.0 = 25 + 200 = 225 = 220

multip