The yo-yo shown in the figure has an outer radius, r, = 1 in. The string is
wound around an inner peg of radius, r~ = 1/4 in. The yo-yo weighs 0.2 lb
and can be treated like a uniform disc or radius T0.
Find: 1. The acceleration o
Quiz 11: Name:
The rear-wheel drive truck is accelerating to the
left while towing the boulder B.
a). Draw the freebody-kinetic diagram for the truck.
include all forces and accelerations.
b). Express with an equation how will you det
Quiz 10: Name:
The wheel is rolling to the right.
It travels at a constant speed of
4 m/s. Find the velocity of
points C and point D.
Use the velocity of the wheel ( = 4 ) to find .
Point B is an instantaneous center so I can reference
Quiz 11a: Name: _SOLUTIONS_
In the following diagram, wheel C rolls to the right without slip.
a). Draw the velocity vector (direction only) for point C.
b). Draw the velocity vector (direction only) for point B.
c). Find and label the instantaneous cente
Quiz 9: Name: _Solution_
The bucket is hoisted by the rope that
wraps around a drum wheel. The
angular displacement of the wheel is
= + 15( rad), where is in seconds.
(a) How far has the bucket moved from 0 = to 4= s?
y = 57.0 = + 15 = 69
Quiz 8: Name: _SOLUTIONS_
The man M jumps off the
dock with a horizontal
velocity of 10 ft/s and lands in
boat B. Both move forward at
3 ft/s. If the man weighs 150lb and the boat was initially at rest,
how much does the boat weigh?
By Conservation of mom
The spring in the diagram has an unstretched
spring length of = 15 . and a spring stiffness
of = 2/. How much work is done by the
spring when the slider moves from point A to
The work done by a spring is
Quiz 4: A 100 lb mining
sled is being pulled up a
mine shaft by a motor
and pulley system. The
motor provides a force of
30 lbs and the coefficient
of friction is = 0.25.
Draw the free body diagram and kinetic diagrams needed to solve
Quiz 2: A particle with an initial velocity of = 12 /
accelerates with a rate of = 2 / 4 + . What is the total
distance the particle has traveled after 10 seconds? What is its
position after 10 seconds?
We begin by setting o
Quiz 3: A car exits the highway and is
traveling with a speed of 72km/hr
(20m/s) at point A. The exit ramp is
circular with radius . If the acceleration
of the car is not to exceed 2.0m/s2, find:
1). the smallest radius, , if the car mai
A) Write an expression for the length of the rope
in terms of the variables ZA & X8, where the
distances XA & XB, represent the location of
points A and B as measured from point D.
B) If plane A is traveling at VA 600 km/h and plane B
Feb. 16th 2015
Your Name _SOLUTIONS_
Your Seat # _
This exam should have 4 pages, with 3 problems adding up to 100 points.
The last page is blank and can be used as scrap paper for computations and checking answers.
i + (~t
o~ ~9~1 ~
cfw_16t2i + 4t3j + (5t + 2)k m/s, where t is in second
Problem 1 [25 pts]
Find the force P required to accelerate the block up the hill
at 5 ft/s2.
P77~q~ 300 +P-j-Pcoc3o
The crankshaft AB is rotating at a constant angular velocity
of v = 150 rad>s. Determine the velocity of the piston P at
the instant u = 30.
x = 0.2 cos u + 2(0.75)2 - (0- 2 sin u)2
x = -0.2 sin uu + C (0.
A uniform rod having a weight of 10 lb is pin supported at A
from a roller which rides on a horizontal track. If the rod is
originally at rest, and a horizontal force of F = 15 lb is
applied to the roller, determine the acceleration of the
o~- P~k~ V(e)~o
Dynamics Practice Exam #2
You are designing an epic playground with a slide 5 meters tall. If the coefficient of kinetic
friction between the slide and clothing is 0.5 and children shouldnt leave the slide traveling
more than 4 m/s.
Initially the motor on the circular saw turns its drive shaft at
v = 120t2>32 rad>s, where t is in seconds. If the radii of gears
A and B are 0.25 in. and 1 in., respectively, determine the
magnitudes of the velocity and acceleration of a tooth C on
The 50-kg crate is pulled by the constant force P. If the crate
starts from rest and achieves a speed of 10 m>s in 5 s, determine the magnitude of P. The coefficient of kinetic friction
between the crate and the ground is mk = 0.2.
If the 50-kg crate starts from rest and travels a distance of 6 m
up the plane in 4 s, determine the magnitude of force P acting
on the crate. The coefficient of kinetic friction between the
crate and the ground is mk = 0.25.