ENSC 017
Kinetics: Force & Acceleration
PROBLEM SET 3
OBJECTIVE: This task is meant to assess how well you understood the topics and how you can apply
them in answering problem solving questions.
DIRECTIONS:
1. The student is required to work on the problem set individually. Any student found guilty of
committing intellectual dishonesty will be penalized in accordance with the prevailing university
rules and regulations.
2. Do not round-off during calculations.
3. Summarize and write your final answers in 3-decimal places. Enclose your final answer/s in a box.
Problem 1
Problem 5
Determine
the
time
needed to pull the cord
at B down 4 ft starting
from rest when a force
of 10 lb is applied to
the
cord.
Block
A
weighs 20 lb. Neglect
the mass of the pulleys
and cords.
The collar A, having a mass of 0.75 kg, is
attached to a spring having a stiffness of
k = 200 N/m. When rod BC rotates about the
vertical axis, the collar slides outward
along the smooth rod DE. If the spring is
unstretched when s = 0, determine the
constant speed of the collar in order that
s = 100 mm. Also, what is the normal force
of the rod on the collar? Neglect the size
of the collar.
Problem 2
Block A has a weight of 8 lb and block B
has a weight of 6 lb. They rest on a surface
for which the coefficient of kinetic
friction is µk = 0.2. If the spring has a
stiffness of
Problem 3
Problem 6
The 1.5 Mg sports car has a tractive force
of F = 4.5 kN. If it produces the velocity
described by v-t graph shown, plot the air
resistance R versus t for this time period.
The pendulum bob B has a mass m and is
released from rest when
= 0o. Determine
the tension in string BC immediately
afterwards, and also at the instant the bob
reaches the arbitrary position
Problem 7
Problem 4
The 2-kg block B and 15-kg cylinder A are
connected to a light cord that passes
through a hole in the center of the smooth
table. If the block travels along a
circular path of radius r = 1.5 m, determine
the speed of the block.
The box has a mass m and slides down the
smooth chute having the shape of a
parabola. If it has an initial velocity of
v0 at the origin determine its velocity as
a function of x. Also, what is the normal
force on the box, and the tangential
acceleration as a function of x?
Ref: R.C. Hibbeler, Engineering Mechanics 14th Edition