Session #3
Frequency Distributions, Histograms, Stemand-Leaf Plots
Say it with pictures
MATH 140
Example: Sorting eggs by weight
Example: Grade distribution
The department head wants to compare the ex
Session #2
Averages
Measures of central tendency
MATH 140
Does your brain compute averages?
Yes. All the time!
Example: You get 60 on your exam. Are you
happy?
Case #1: the class got [35, 40, 28, 32,
Session #1
MATH 140
About me
PhD in Computer Science
Budapest, Hungary
Munich, Germany
MBA from Montclair State Univ.
I had good math teachers:
Teaching math at NJIT and NJCU.
Prof. Ern Rubik
Working
3. Use the method of trigonometry to determine the resultant
of the two forces acting on the eye-hook as shown. Give your
answer in polar coordinate and rectangular coordinate form.
25
25
5N
8N
Defini
Problem 1. A 200-kg load is supported by the rope-and-pulley arrangement.
Determine the magnitude and direction of the force P required at the free end
of the rope to maintain equilibrium.
The cable t
#1. A force, F = 12i + 3j +4k (lbs), passes through the point
A( -3, 4, + 12). A couple, C = 10k, is applied to the same point.
Find an equivalent force system at the origin.
Draw what you have and se
#1. A 6-ft long fishing rod AB is anchored in the sand. The force in the
fishing line, BC, from the fish pulling is 10 lb. Determine the moment
due to this force about A where the fishing rod is ancho
Mech 234/5
Fall 03
EXAM 2
-Problem 1
Given points A(4, 3, 2), B(6, 1, -2) & C(8,
8, 4), find the angle between the lines AB & AC.
AB = 2i - 2j - 4k
AC = 4i + 5j + 2k
AB AC = AB AC cos = 8 10 8
= -10
A
Suggestion:
1. Pay attention to the directions of the
vectors shown.
2. Anticipate the quadrant for your final resultant.
Rx > 0 and Ry > 0, R is in the first quadrant.
3. Hypotenuse of 3 and 4 = (3^2
PARTICLE EQUILIBRIUM
When the resultant (vector sum) of all forces acting on a
particle is zero, the particle is said to be in equilibrium.
F2
F1
F1 +F2 + F3 + F4 + F5 = 0
F5
F3
F4
For the particle sh
1722 Kennedy Blvd
Union City, NJ 07087
March 22, 2016
Martha Kein
Department of Humanities
Cullimore Hall
University Heights
Newark, New Jersey 07102
Dear Professor Kein:
I hope all is well and you en
Equivalent Force-Couple Systems
Stated simply, it's a redesign to replace what you have in the original system with a new system
that has the same end effect.
Case 1.
There is one force on a rigid bod
W22. a m
W.
5? a; -
ekwhww , $13,;
Amm EQUILIBRIUM
ZF=0
Therefore,
Action down
+
Reaction up = 0
These forces cause a
TWISTING ACTION
or TORQUE (moment)
on the pin in the pinwhee ".
the PIN must RESIS
Solutions suggested by Milano
Problem 4.21 Beer and Johnston
Determine the reactions at A and C when = 30.
Hint: Consider the horizontal and vertical relations of the reaction relative to the ramp.
80
Problem 1 Given three forces in the x-y plane, A, B & C, where A
is 20# and acts at an unknown angle from the x-axis, B is 25#
and acts on a slope of 3H:4V and C is 26# and acts on a slope of
5H:12V.
Problem 3. The hook is acted on by three forces. Given that the
resultant is 90i kN, determine the magnitude of P and the angle,
.
y
P
R = F
Fx = 90 = P cos + 40 cos 60 - 30
30 kN
R=90i
x
60
90 + 30 4