Part 1. Getting Out in the World (1.1) Drawing artifacts (5 pts) Find an interesting artifact in your kitchen, garage, or dorm room that is operated by a force or moment. Create a storyboard (cartoon-like description) of how the artifact works, including how the force or moment operates it. Examples of artifacts include a hand mixer, a hole punch, a nail clipper, the machines in the weight room, or a car jack. 1. Hand Mixer 2. Exert force at the handle for gripping. 3. Impose moment along the handle to mix batter F F M
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Part 1. Getting Out in the World
(1.1) Drawing artifacts (5 pts) Find an interesting artifact in your kitchen, garage, or dorm room that is operated by a force or moment.
Create a storyboard (cartoon-like description) of how the artifact works, including how the force or
moment operates it. Examples of artifacts include a hand mixer, a hole punch, a nail clipper, the machines
in the weight room, or a car jack.
1. Hand Mixer 2. Exert force at the
handle for gripping.
3. Impose moment along
the handle to mix batter
F
F
M
(1.2) Calibrating Your Capacity (5 pts) It is important for engineers to have a sense of how large forces are. One way of developing this sense is
to create reference frames for force comparison; one such reference is your physical capacity. To this
end, find a weight room on campus and record the following information, in the table format shown
below in Table 1. Rather than turning in the table, please input your results at the following link (this is
(2.1) Read: βThe Bicycle: βStaticβ doesnβt mean that you arenβt movingβ
Goal: To provide a free-body diagram of the bicycle and cyclist traveling at constant speed, estimate the
maximum velocity on a bicycle if the coefficient of drag is reduced by 15% and provide two suggestions
on how to reduce aerodynamic drag.
Given: The values of the variables, which include π΄πππππ‘ππ = 0.5π2, πΆπ = 0.85 Γ πΆπβππππππππ = 0.765
Assume: Since the question asks for maximum velocity, βπππππβ = 167π. This is selected based on the
assumption that the cyclist sustains peak force throughout the stroke. Also, it is assumed that the cyclist is
cycling at sea level, which makes the air density π = 1.2ππ/π3 for the problem.
Draw: Free-body diagram of the bicycle and the cyclist
Ways to Reduce Drag: The cyclist can wear a tighter clothes, an aerodynamic helmet, or use more
aerodynamic bike wheels.
ππππ₯ = 27.0π/π
(2.2) Read: βThe Golden Gate Bridgeβ
Goal: To provide a free-body diagram of the bridge, estimate the minimum required anchorage weight if
the coefficient of friction is increased by 15% and two suggestions of how to increase the coefficient of
friction.
Given: Friction force that prevents sliding, βππππππ‘πππ,πππβπππππβ = 236.5ππ, vertical force from table,
Part 3. Representing and Labeling Forces & Vectors
Make sure that your answers to the problems in this section include all calculations you performed and a
supporting drawing(s).
Furthermore, show only the number of significant figures appropriate for precision of given data: A
practical rule in engineering calculations is to use four figures to record numbers with a leading β1β and
three figures in all other cases in presenting your final answer. Intermediate calculation steps should retain
more significant figures. With this rule, a force of 40 is 40.0 N, and a force of 15 is 15.00 N. Numbers are
generally rounded (as opposed to truncated) in reporting values to the correct number of significant
figures. For example, 29.694 N would be written with three significant figures as 29.7 N with rounding
(and not as 29.6 N, which is what we would get if we truncated the answer).
(3.1) External, Internal and Not-in-System Forces (5 pts) A person grips a pair of locking jaw pliers (more commonly known as vise-grips), as shown in Figure 1,
in order to tighten a nut onto a bolt. Three cases (systems) are described in the top row of Table 2. For
each system identify the external (E), internal (I) and Not-in-System (NIS) forces, and indicate them in
Table 2, including a sketch of each system in the space provided. (It is ok to turn in the next page with
your homework.)
Figure 1
(3.1) continued. (Turn in this page with your homework)