Phys 124 Assignment # 3
REASONING AND SOLUTION The apparent weight is
FN = mw(g + a)
We need to find the acceleration a. Let T represent the force applied by the
hoisting cable. Newton's second law applied to the elevator gives
CH 9 144
Use a constant angular acceleration equation and solve for
0 z .
SET UP: Let the direction of rotation of the flywheel be positive.
0 0 z t 12 z t 2
CH 11 144
11.13. IDENTIFY: Apply the first and second conditions of equilibrium to the strut.
(a) SET UP: The free-body diagram for the strut is given in Figure 11.13a. Take the origin of coordinates at
the hinge (point A) and
be the horiz
CH 5 144
to each weight.
Two forces act on each mass: w down and
T ( w)
EXECUTE: In all cases, each string is supporting a weight w against gravity, and the tension in each string is w.
EVALUATE: The tension is th
CH 6 144
The gravity force is constant and the displacement is along a straight line, so
W Fs cos .
SET UP: The displacement is upward along the ladder and the gravity force is downward, so
1800 300 1500. w mg 735 N.
W (735 N)(
Ch 3 In Class Problems
IDENTIFY: The person moves in projectile motion. She must travel 1.75 m horizontally during the time she
falls 9.00 m vertically.
SET UP: Take
ax 0, a y 9.80 m/s 2. v0 x v0 , v0 y 0.
Time to fall 9.00 m:
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Wtot K B K A.
The forces on the rock are gravity, the normal force and friction.
at point B and let
W f 022 J. K A 0.
y A R 050 m.
The work done by friction is
The free-body diagram for the rock
CH 14 144
Compare the specific
given in the problem to the general form
A 740 cm, 416 rad/s,
x (t )
x A cos( t ).
k m 2 (150 kg)(416 rad/s) 2 260 N/m
Assignment # 8 Due to Friday Nov 18th, 2016 PHYS 144
8.10. IDENTIFY: Apply
J x p x mv2 x mv1x
J y p y mv2 y mv1y
to relate the change in
momentum to the components of the average force on it.
SET UP: Let
be to the right and be upward.
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J x p2 x p1x .
We know the initial momentum and the impulse so can solve for the final
momentum and then the final velocity.
SET UP: Take the x-axis to be toward the right, so
v1x 300 m/s
J x Fx t
to calculate the impulse,
CH 10 144
10.3.IDENTIFY and SET UP:
to calculate the magnitude of each torque and use the right-hand rule (Figure
10.4 in the textbook) to determine the direction. Consider Figure 10.3.
Let counterclockwise be the positive sense of rot
CH 4 144
IDENTIFY: Vector addition.
SET UP: Use a coordinate system where the
is in the direction of r the force applied by
dog A. The forces are sketched in Figure 4.1.
FAx 270 N, FAy 0
FBx FB cos 60 0 (300 N)cos 60 0 150 N
Student Name: ANSWER KEY Course:
E RROR AND G RAPHICAL A NALYSIS W ORKSHEET
For each section of this assignment, first read the relevant section in the Yellow Pages of your Lab Manual.
All rough work should be done on se
Phys 124 Assignment # 2
36. REASONING The players collide when they have the same x coordinate relative to a common
origin. For convenience, we will place the origin at the starting point of the first player. From
Equation 2.8, the x c
Physics 107 HOMEWORK ASSIGNMENT #3
Cutnell & Johnson, 7th edition
Chapter 3: Question 12, Problems 34, 44, 56
Chapter 4: Problem 8
12 Two balls are launched upward from the same spot at different angles with respect to the
ground. Both balls rise to the s
PHYS144: Tutorial Problems 1
You are strongly encouraged to read and discuss these problems amongst yourselves before the
tutorial. Please remember to bring your iClicker to the tutorial which will be held directly after the
1. In ancient batt
EVALUATE: In 5.0 s he can only reach about 2/3 the speed of sound without blacking out.
IDENTIFY: For constant acceleration, the standard kinematics equations apply.
SET UP: Assume the ball starts from rest and moves in the