ASSIGNMENT 2
Textbook Assignment:
“The Screw,” chapter 5, pages 5–1 through 5–4; “Gears,” chapter 6,
pages 6–1 through 6–8; “Work,” chapter 7, pages 7-1 through 7–6; and
“Power,” chapter 8, pages 8–1 through 8–4.
2-3.
How do you find the theoretical
mechanical advantage of a
jackscrew?
1.
Divide the amount of resistance
by the amount of effort
2–1.
What is the pitch of the screw
figure 2A?
1.
1/16 in
2.
1/2 in
3.
1 4/7 in
4.
3
in
in
2–2.
Upon which measurements does the
theoretical mechanical advantage of
a jackscrew depend?
1.
Pitch and length of the screw
2.
Length of the jack handle and
radius of the screw
3.
Pitch and radius of the screw
4.
Length of the jack handle and
pitch of the screw
required to overcome the
resistance
2.
Multiply the length of the jack
handle by the radius of the
screw and then divide by the
length of the screw
3.
Multiply the length of the jack
handle by 2rr and then divide by
the pitch of the screw
4.
Divide the length of the jack
handle by 27r and then multiply
by the pitch of the screw
2–4.
High friction losses are built into
a jackscrew in order to prevent the
1.
screw from turning under the
weight of a load as soon as the
lifting force is removed
2.
screw from becoming overheated
when a load is being lifted
3.
threads of the screw from being
sheared off by the weight of a
load
4.
jack from toppling over as soon
as the lifting force is removed
2–5.
If a screw has a pitch of 1/16
inch, how many turns are required
to advance it 1/2 inch?
1.
2
2.
8
3.
16
4.
32
12
