Due Friday, September 8th , 4pm
PHY E221 (Fall 2017)
Homework Set # 1
Please do write legibly as much as you possibly can. The instructor will be grateful for a clear presentation
of your work! Also,
Which of the following is not a frictional force between solids?.The
correct answer is: viscosity
Which of the following is the sign of the scalar product of two vectors that
have an angle of 79 betwe
From the following choices select the one that is not required for making
quantitative statements about the worldThe correct answer is: a
regional unit system
Sue throws Sam the keys to the car. The k
When turning around a circle, a car is subject to a continuous force, but its
speed does not necessarily change.The correct answer is: The speed is
not changing, but the direction is.
How fast, in m /
Which of following is the resultant gravitational force acting on the 100 kg
mass in the diagram?.The correct answer is C: 1.56x10^-6N
How many centimeters are in 2.3 meters?.The correct answer is: 23
Suppose the two rods A and B are moving at two speeds (1/4)c and (3/4)c,
respectively, relative to an observer O at rest. .The correct answer
is:LA>LB
If a radius of a pipe carrying water is doubled,
Paul has a mass M and a volume VpThe correct answer is:PwVpgmg
An observer O notes a particle moving to the right with velocity v. Another
observer O is moving with speed v relative to O along the dir
You are in a mall and are hurrying to get to the candy store before it closes.
You walk on an escalator to speed up your progress.The correct
answer is: 1.6 s
Which of the following is correct concern
A ceiling fan has four blades. The distance between the center of the fan
and the tip of the blade is 0.75 m. The fan is spinning at 300 rev / min
The correct answer is: 75.5g
When a small car pulls a
The MichelsonMorley experiment is important in the context of Einsteins
special theory of relativity primarily because.The correct answer is: it
indicated that there is no absolute frame of reference
A small airplane and a hot air balloon are moving horizontally towards each
other. Relative to the ground, the plane travels at a speed of 135 m / s and
the balloon travels at a speed of 7 m/s.The cor
The distance along both the axes, as shown in the drawing below, are in
meters. Which of the following is the resultant gravitational force vector
acting on the 100 kg mass at the origin of the diagra
Two identical boxes are moved in equal distances in the horizontal
direction. Box A experiences a constant net force F applied at an angle to
the horizontal and box B experiences.The correct answer is
Three pool balls of equal mass are resting on a horizontal frictionless
surface. The cue ball (Ball 1) of mass 700 g is rolled.The answer is B: v
= 3.00 m / s F = 42.0 N
A rolling pin rolls down a 2-m
If y = 0 is chosen to be at the ground level, which of the following is the
gravitational potential energy of a 500 lb weight that was lifted 3 ft from
ground level?.The correct answer is:1.50x10 ftlb
A ride at an amusement park begins by spinning patrons about a circle of
radius R with constant speed v. At some point during the ride the speed
doubles a?.The correct answer is: a
The raising and low
A steel playground slide is 5.25 m long and is raised 2.75 m on one end. A
45.0 kg child slides down from the top starting at rest. The final speed
bottom is 6.81 m/s.The correct answer is: 31.7 N
A p
A bar weighting 100 N and 2 m in length, is held up by two strings that are
made out of different materials. The string on the left will break if the
tension goesThe correct answer is: 0.71 m
The hang
The radius of the Moon is known to be 1.7 10 m. Astronauts who walked
on the Moon measured the time it takes an object to fall 1 m on the Moon
to be about.The correct answer is: 7.1 10 kg
Using the co
A uniform disk of mass M and radius R is rotating on an axle with constant
angular velocity W. MR^2The correct answer is C:1/6MR^2W^2
What would happen to the precession of a gyroscope if it were spin
In a game of marbles, a 60 g marble is rolling at 8.00 cm / s when it collides
with a stationary marble. the 60 g marble takes off at a 27. The correct
answer is: 0.0800 kg
A 309 g glass rolls down an
What is the acceleration of a skydiver at terminal velocity whose mass is 80
kg and cross-sectional area is 14 m2.The correct answer is: 0 m / sec2
Consider a spring that is stretched from its equilib
Which of the following is not a vector?The correct answer is: 2 kg of mass
under a table
Which graph best illustrates the following description of motion? A car starts
at rest, accelerates at a consta
If a vector of magnitude 12 pointing in the xdirection is vector multiplied by
a vector of magnitude 6 pointing in the ydirectionThe correct answer is:
72
A stunt man is sliding down the side of a mou
The following graphs show the position, velocity and acceleration of a car
trip taken by Zeno on a long straight highway from Boston to Springfield.
The correct answer is: Zeno might have seen a polic
Torque is given by d formula t=FxD 2.4N, 17 cmThe correct answer is:
0.41 Nm
In a traffic accident, two motorcycles, A and B, collide with each other. 180
kg and 134 kg.50 m / s , what is the acce mot
Assume that the Moon is in circular orbit around the Earth. approximately
3.56 10 km. approximately 28 days. Moon in km / h ?.The correct answer
is: 311 km / h
If you are observing a moving object, wh
A 100 N object sits on a table and is tugged forwards by forces F =1000 N
and F = 1500 N, as shown. What is the magnitude of the normal force, F ?
The correct answer is: 100 N
What is the difference b
A ball is thrown vertically up into the air. It reaches a maximum height 34 m
above
the point where it was released. What is its initial velocity?.The correct
answer is: 26 m / s
Calculate x=vt+1/2at^
Two vectors can be added graphically byThe correct answer is: adding
them tip to tail
Which of the following is not an example of a vector?.The correct answer
is: mass
Which of the following pairs of