Problem # 42 of 120
Centripetal force is:
a)A force that is associated with the rotation of a rigid body.
b)A force that is directed towards the center of rotation
c)A force that is in the opposite direction of the centrifugal force.
d)All of the above.
Problem # 47 of 120
Which of the following is a correct representation of Newton's Law?
= ma/g.
= gma.
= m/a.
= ma.
Problem # 48 of 120
A constant force of 1 Newton is applied horizontally to a 1 kg mass. What is the particle's horizontal
a)1000 m/sec2
b)2 m/sec2
c)0.5 m/sec2
d)1 m/sec2
Problem # 57 of 120
A block weighing W = 10 lbs is being pushed by force P = 5 lbs as shown in Figure #1. If the block is
stationary what is the angle of friction?
Figure #1
a)30.00 deg
b)26.56 deg
c)63.43 deg
d)60.00 deg
At this point I began to copy all dynamics problems.
Problem # 60 of 120
The force F of 10 lbs is initially applied at point A to a 10 lb rigid body positioned flat on a frictionless horizontal
plane as shown on Figure #1. What is the angular acceleration a, moment M, and instantaneous value of ro
given Ic = 0.02 slug-ft2. Point C is the center of gravity, and point O is the instantaneous axis of rotation. Note:
point O is not fixed.
Figure #1
a)a = 122.33 rad/sec2 , M = 3.334 ft-lb, ro = 0.224 ft
b)a = 98.87 rad/sec2 , M = 2.113 ft-lb, ro = 0.153 ft
c)a = 117.85 rad/sec2 , M = 2.357 ft-lb, ro = 0.193 ft
d)a = 55.76 rad/sec2 , M = 1.206 ft-lb, ro = 0.098 ft
Problem # 69 of 120
What is the mass moment of inertia about the center xc-axis for the 3 cm x 5 cm, 1 kg thin plate shown in
Figure #1.
Figure #1
a)0.85 kg-cm2
b)11.25 cm4
c)0.75 kg-cm2
d)0.75 kg-cm2
Problem # 72 of 120
Given a spring constant of 10 N/cm, what is the potential energy of the spring if it is compressed 10 cm?
a)37 Joules
b)50 Joules
c)4.9 Joules
d)5.0 Joules
Problem # 81 of 120
An airplane accelerates uniformly during takeoff from rest to 200 mph in 90 seconds. What is the planes
a)4.88 ft/sec2
b)3.26 ft/sec2
c)16.1 ft/sec2
d)2.21 ft/sec2
Problem # 87 of 120
A 20 kg, 0.5 m diameter steel drum is rolled 10 m along a level floor. What is the change in the drum's
potential energy relative to the floor?
a)0 N-m
b)19.7 N-m
c)20 N-m
d)5 N-m
Problem # 88 of 120
How much would a 150 lb man weigh if he was to stand on a scale in an elevator that is accelerating upward
at 2 ft/sec2 ?
a)150 lb
b)159 lb
c)141 lb
d)162 lb
Problem # 91 of 120
How much torque is required to accelerate a 3 lb, 30 inch diameter bicycle wheel from 0 rpm to 60 rpm in 1
minute? Assume the bicycle wheel is a solid thin disk.
a)6.9 ft-lb
b)0.000798 ft-lb
c)0.0479 ft-lb
d)0.15 ft-lb
Problem # 92 of 120
An 1 lb iron object is placed on a table 2 feet from a fixed magnetic as shown in Figure #1. If the force in
pounds the magnetic field exerts on the iron object is defined as F = 4/x, where x is the distance in feet from
the magnet, what would be the objects velocity when it is 1 ft from the magnet. Assume a frictionless table.
Figure #1
a)89.30 ft/sec
b)64.78 ft/sec
c)6.68 ft/sec
d)9.44 ft/sec
Problem # 93 of 120
A 10 foot long ladder as shown in Figure 1 is sliding down the wall. If Point B is moving at 5 feet per second,
what is the velocity of Point A?
Figure #1
a)-2.88 ft/sec
b)-5.00 ft/sec
c)-8.66 ft/sec
d)-10.00 ft/sec
Problem # 94 of 120
The polar moment of inertia is:
a)the same as the radius of gyration.
b)the inertia of a solid about the origin of an x-y-z coordinate system.
c)the inertia of an area about an axis perpendicular to the plane of the area.
d)the inertia of an solid about an axis perpendicular to its centroid.
Problem # 96 of 120
Problem 1
A baseball pitcher throws a baseball from a standing position towards home plate. The pitcher releases the
ball parallel to and 5 ft above the ground at an initial velocity of 100 miles/hour. How high is the baseball from
the ground at home plate? Assume home plate is 60 ft away from the pitcher and neglect air friction.
a)2.7 ft
b)2.3 ft
c)4.3 ft
d)3.7 ft
Problem # 97 of 120
A car as shown in Figure #1 passes by you on a path defined as x = 50 ft. If the cars position is y = 50(t) ft (t
is in sec), what is the angular velocity (w) of the automobile relative to you at t = 0 seconds and at t = 1.0
Figure #1
a)w(0 sec) = 1 rad/sec, w(1 sec) = 0.5 rad/sec
b)w(0 sec) = 0.5 rad/sec, w(1 sec) = 0.5 rad/sec
c)w(0 sec) = 1 rad/sec, w(1 sec) = 1 rad/sec
d)w(0 sec) = 0.7 rad/sec, w(1 sec) = 0.7 rad/sec
Problem # 98 of 120
A ball is connected to a string and whirled in a 10 ft diameter circle at the rate of 5 revolutions per second. If
the ball weighs 1 lb, what is the tension in the string that causes the rotation?
a)88 lbs
b)223 lbs
c)153 lbs
d)76 lbs
Problem # 101 of 120
A bullet weighing 5 grams, traveling at 500 ft/sec is shot into a phonebook. If the bullet penetrates the phone
book 1 inch, what is the average force delivered to the phone book ? Note - the phonebook is stationary, fixed
in position unable to move.
a)43 lbs
b)1213 lbs
c)513 lbs
d)88 lbs
Problem # 107 of 120
How high off the ground would a car have to be in order for its potential energy to equal its kinetic energy if it
was traveling at 60 mph?
a)47 ft
b)120 ft
c)98 ft
d)235 ft
Problem # 108 of 120
A 20 lb weight is hung from two springs that are hooked in series as shown in Figure #1. What is the total
potential energy of the two springs if the spring constant for each spring is 10 lb/in?
Figure #1
a)160 in-lb
b)80 in-lb
c)20 in-lb
d)75 in-lb
Problem # 110 of 120
A force F is applied 1 ft from the center of gravity C of a 10 lb block of wood floating on the water as shown in
Figure #1. What is the distance q (the instantaneous axis of rotation from point Z to F)? The mass moment of
inertia about the axis perpendicular to the block of wood at C is 0.1 slug-ft2. Neglect friction between the wood
and water. Assume the block is initially at rest.
Figure #1
a)1.322 ft
b)0.322 ft
c)0.750 ft
d)0.333 ft
Problem # 114 of 120
Given: r = xi + yj is a position vector of a point in a rectangular coordinate system as shown in Figure #1
x = 2t (time)
y = 4t2
What is the angle (f) between the velocity vector (vt) to the x-axis ?
Figure #1
a)63.43 deg
b)19.44 deg
c) 82.87 deg
d)0 deg
Problem # 115 of 120
An example of a body undergoing simple harmonic motion is a:
b)free falling weight.
c)shaft of a motor.
d)water in a whirlpool.
Problem # 116 of 120
A 1 lb solid steel ball with a radius of 1 inch is rotating about and 5 ft from a fixed axis. If distance from the axis
is increased to 6 ft, what is the change in the mass moment of inertia about the axis of rotation for the steel
a) 1.125 slug-ft2
b) 0.342 slug-ft2
c) 0.776 slug-ft2
d) 0.171 slug-ft2
Problem # 117 of 120
What is the polar radius of gyration (r) for the 10 g mass shown in Figure #1? The centroidal moments of
inertia are Ixc = 25 g-cm2 and Iyc = 10 g-cm2.
Figure #1
a)3.500 cm
b)1.871 cm
c)1.581 cm
d)5.000 cm