Motion Diagrams
Marsha is moving upward in a hot air
balloon at 5 m/s when she drops Harry .
Draw a motion diagram for Harry beginning the instant he is
dropped. Hint: Try drawing one first beginning 10
seconds before he is dropped!
a. Draw a motion diagram of an object with
positive velocity and positive acceleration.
b. Draw a motion diagram of an object with positive velocity
and negative acceleration.
c. Draw a motion diagram of an object with
negative velocity and positive acceleration.
d. Draw a motion diagram of an object with negative velocity
and negative acceleration.
Displacement, Velocity, and
Acceleration Curves
Construct displacement, velocity and
acceleration vs time curves for :
A dog walking with constant speed away from
home.
The cart given a shove then released up
the ramp below.
Describe the motion of the objects
The graphs on this
page represent the motion of objects along a line which is the positive
distance (position) axis. Notice
that the motion of objects is represented by distance, velocity, or
acceleration graphs. Answer the following
questions. You may use a graph
more than once or not at all, and there may be more correct choices than
blanks. If none of the graphs is
correct, answer J. 16. Pick one graph that gives enough
information to indicate that the velocity is always negative. Pick three graphs that
represent the motion of an object whose velocity is constant (not changing). 17. 18. 19. 20. Pick one graph that definitely
indicates an object has reversed direction. 21. Pick one graph that might possibly be
that of an object standing still. Pick 3 graphs that
represent the motion of objects whose acceleration is changing. 22. 23. 24. Pick a velocity graph
and an acceleration graph that could describe the motion of the same object
during the time shown. 25. Velocity graph. 26. Acceleration graph. |
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13. The following is a velocity-time graph
for a car.
What is the average
acceleration of the car? Show your
work below.
What is the total change
in displacement of the object between time = 2 sec and time = 8 sec ?
The following is an
acceleration vs time graph for a car
What is the total change
in velocity between t = 2sec and t = 6 sec ?
Kinematic Eq of
Motion
A metro train in Washington, D.C., starts
from rest and accelerates at 2.0 m/s2 for 12 s. The train travels at a constant speed for 65 s. The speed of the train then decreases
for 24 s until it comes to a stop.
What is the total distance between stops?
Projectile Motion
Chapter 4 Newton's Laws of Motion Force
and Velocity Vectors
1. Draw
sample vectors to represent the force of gravity on the ball in the positions
shown above (after it leaves the thrower's hand). Neglect air drag. |
2.
Draw sample bold vectors to represent the velocity of the ball in the
positions shown above. With lighter vectors, show the horizontal and vertical
components of velocity for each position. Neglect air drag. |
3. (a) Which velocity component in the
previous question remains constant? Why?
(b) Which velocity component changes
along the path? Why?
Mathematical Aspects
Conceptual and physical aspects are
essential, and the best way to begin a study of projectile motion. However, projectile motion problems can
appear to be a vast array of "types" of problems to learn, unless you
get mathematical!
So how many different ways are there to
slice this apple, really? How many
numbers in each of the following problems?
A) 5 kg Mass
B) 50 kg mass
C) They both go the same height, but it takes the 50 kg mass
longer to get to that height.
D) The both go the same height in the same time.
A) 5 kg Mass
B) 50 kg mass
C) They both go the same height, but it takes the 5 kg mass
longer to get to that height.
D) The both go the same height in the same time.
5. A battleship
simultaneously fires two shells toward two enemy ships, one
close by (A), one far away (B).The shells leave the battleship at
different
angles and travel along the parabolic
trajectories indicated below.Which
of the two enemy ships gets hit first?
Explain.
FBD's
Determine the normal
force on each block below
An 80 kg student is
lifted from rest to a height of 10 m by a rope that passes around a
pulley. An 84 kg block is
attached to the other end of the rope. |
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The elevator shown at
right is initially moving upward at 12 m/s. The force of the bottom rope on the bottom box is 675 N. |
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Energy
If she pushes the
barrel with constant velocity,
What
is the net work done on the barrel?
What is the work done on the barrel by gravity?
What
is the work done by the stevedore?
QUESTION 3: A bottle
dropped from a balcony strikes the sidewalk with a particular !speed. To double the
speed of impact you would have to drop the bottle from a balcony that is
1. twice as high
2. three times as high
3. four times as high
4. five times as high
5. six times as high
6. eight times as high
7. impossible to
determine
How much energy is
required to slow a 500 kg boat
from 20 m/s to 5 m/s ?
How much energy is
required to hurl Chicopee (mass =
.3 kg) to a height of 40 m above the ground?
14. A truck initially at rest at the top of
a hill is allowed to roll down without friction. At the bottom its speed is 4
m/s. Next, the truck is again rolled down the hill without friction, but this
time it does not start from rest. It has an initial speed of 3 m/s on top, even
before it starts going down the hill. How fast is it going when it gets to the
bottom?
1. 3 m/s
2. 4 m/s.
3. 5 m/s.
4. 6 m/s.
5. 7 m/s
A
childŐs toy consist of a piece of plastic attached to a spring (Figure below). The spring is compressed 2.0 cm, and
the toy is released. If the mass
of the toy is 100 g and it rises to a maximum height of 60 cm, what is the
spring stiffness constant of the spring?
Rotational Motion
Find the moment of
inertia
Inner radius is a, outer
radius is 2a, all masses are m
if pivot point is at
center
if pivot point located
Rot Kinetic Energy
A 20 kg sphere with
radius 2 m rolls on table top with
a speed of 30 m/s. What is itŐs
total kinetic energy?
A solid disk has a speed
of 30 m/s at the bottom of a 37ˇ incline.
How far up the incline does it roll before coming to a halt?
Conservation of Linear momentum
A 60 kg kid on a 200 kg
bumper car is moving to the east at 30 m/s. He has a head-on perfectly elastic collision with another
identical car that is moving west at 30 m/s and containing two large adults. The kidŐs car bounces back in the
direction from which he came at a speed of 100 m/s, while the adults car
bounces backward at a speed of 5 m/s, how much do the two large adults weigh in
newtons?
Impluse
Impulse - Momentum
A force of 500 N is
applied to a wagon of mass 400 kg opposite itŐs direction of motion for 1
minute.
What is itŐs change in velocity?
What is it's power
output?
Rotational Dynamics,
Torque
Moment of inertia of the
wheel is I. What kind of questions
could we ask?
Static Equilibrium
Which tension is the
greatest ?