# 1 Physics 20 10 Summer 2016 Richard In "chretsen Exam 2

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1 Physics 20 10 Summer 2016 Richard In "chretsen Exam 2
```Summer 2016
Physics 20 10
Richard In "chretsen
Exam 2
Name:
UNID:
TA: \r*(_ v<9 r
A.
B.
1
For each of the following trajectories, draw in the specified vectors at the 5 points along the object's path. Keep
in mind that a vector's length displays its magnitude.
x-component of velocity
y-component of velocity
total velocity
acceleration
For each of the following quantities, state whether it is a vector or a scalar.
Displacement
vixArt-
Speed
IC^A*^
Tension force
Velocity
MLi.kfbr
Mass
^u^X^
Distance Travelled
Coefficient of Static Friction
C.
Two strings are tied to a box of mass 56.0 kg that rests on africtionless table as
shown by this top view. Each string pulls with a force of magnitude 30.0 N.
1.
Draw a free-body diagram of this top view.
Be careful...you may not be used to this vantage point.
Top View
5
T,
2.
Calculate the x-component and y-component of the acceleration that the box feels. Then, find the total
acceleration vector that the box feels.
T. v*% 0s) - T,
F • ^ T L* *\
dL
"• ^ " - "
(T
\
Physics 20 10
Summer 2016
Richard Ingcbrctscn
Exam 2
Name:
UNID:
TA:
fl/JU
2
You are standing in an elevator with two scales. Assume that if you are standing on both scales, your weight is evenly
distributed between both of them. Assume that you have a mass of 65.0 kg. Use the blank force vs. time graph provided
to complete the following.
Read all parts first. Then, label each axis with the appropriate
quantities, numerical labels and units of measure.
Using the following information, draw lines representing the
readings given by both scales for a 10 second elevator ride.
Clearly label these lines "Scale 1" and "Scale 2."
^•--Tt
For the first 4 seconds of your elevator ride, you are standing on
both scales. After that, you are only standing on Scale 1
For the first 2 seconds of your ride, the elevator accelerates
upward. The magnitude of the acceleration is 1.0 m/s2. Then, the
elevator moves upward at a constant speed for 4 seconds. After
that, the elevator has a downward acceleration to come to a stop. (
The magnitude of that acceleration is also 1.0 m/s2 and lasts for 2
seconds. Finally, the elevator is at rest for 2 seconds.
0
— 0 SC^.(A«*3 .
(A.
a
:
^
|V. M
o
ivu -
l*h\s 2010
S u m m e r 201 (>
R i c h a r d lr»<u'bri'lsen I
Exam 1
Name:
UNID:
TA:
A.
3
S^ks^i^
A criminal is escaping across a rooftop and runs off the roof horizontally at a speed of 5.3 m/s. hoping to land on
the roof of an adjacent building. Air resistance is negligible. The horizontal distance between the two buildings
is D, and the roof of the adjacent building isj.0jn below the jumping-off point. Find the maximum value for D.
^X
6
0
t *' J
t .
B.
In the figure, two blocks are connected to
each other by a massless string over a
frictionless^mllev. The mass of the block
on the left incline is 6.00 kg. Assuming
the coefficient of static friction us equals
0.542 for all surfaces, find the range of
va}ues_of the mass of the block on the
right incline so that the system is in
equilibrium.
..» 0.542
T
-,r-*|t*/
As you ride TRAX home, you notice a cyclist riding alongside the train. The train has a velocity +40 injgh with
respect to the road, and the cyclist is keeping up with traffic at+25mpji_with respect to the road. (This guy's
probably a pro cyclist) What is the cyclist's velocity with respect to i train?
\/. = + *o ~-pk
v, *
l»h\sics 2010
S u m m e r 2016
kicluml In^ebretsen
Exam 2
Name:
LJNID:
TA: £<teiuve/
A.
B.
4
Three boxes are lined up on africtionless table so
that they are touching each other as shown in the
figure. Box A has a mass of 20 kg, box B has a
mass of 30 kg^ and box C has a mass of 50 kg. If
an external force (F) pushes on box A toward the
right, and the force that box B exerts on box C is
400 N, find the acceleration of the boxes and the
value of the external force F.
vow ^ea? &e/f;
Wearing a seat belt causes the immense forces generated in collisions to be transferred to more sturdy parts of
your body, resulting in bruising rather than disability. In one collision scenario, a 55 kg. person rides hi a car
travelling at 29.1 m/s (which is about 65 mph). Upon hitting another vehicle, it takes a distance of 1.2 m to come
to a stop. Calculate the amount offeree that the seat belt exerts to bring this person to a stop. Then, as you leave
this test, remember that without wearing a seatbelt, this force would instead be exerted on the person's head by
the steering wheel or windshield.
v* -
This part will be graded. Answer "Right" or "Wrong."
I commit to wearing a seat belt whenever I am in a moving vehicle.
```
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