ENGG MECH AND STREMA PROBLEMS Flashcards
An inverted T object composed of two identical rectangles with 2” width
and 6” length. What is the moment of inertia about its central axis?
a. 460 in4 c. 320 in4
b. 290 in4 d. 170 in4
b. 290 in4
There is a radial clearance of 0.05 mm when a steel tube with
inside diameter of 125.1 mm is placed over an aluminum tube. The
inside diameter of the aluminum tube is 120 mm, and the wall
thickness is 2.5 mm. The aluminum tube is subjected to an internal
pressure of 5 MPa. Use E = 70 GPa for aluminum and E = 200 Gpa
for steel.
What is the internal pressure of the aluminum tube to cause
contact with the steel?
A. 3.003 MPa C. 2.224 MPa
B. 2.381 MPa D. 4.762 MPa
What is the contact pressure between steel and aluminum tubes
when the aluminum tube is subjected to an internal pressure of 5
MPa?
A. 2.50 MPa C. 2.38 MPa
B. 3.56 MPa D. 5.00 MPa
B. 2.381 MPa
B. 3.56 MPa
Block A supports a load W = 100 kN and is to be raised by forcing the
200-wedge B under it. The angle of friction for all surfaces in contact
is f = 15°. If the wedge had a weight of 40 kN, what value of P would
be required
To start the wedge under the block and
a. 110 kN c. 130 kN
b. 140 kN d. 150 kN
To pull the wedge out from under the block?
a. 49 kN c. 15 kN
b. 28 kN d. 33 kN
c. 130 kN
b. 28 kN
A pipe carrying stream at 3.5 MPa has an outside diameter of 450 mm and a wall thickness of 10 mm. A gasket is inserted between the flange at
one end of the pipe and a flat plate used to cap the end. How many 40 –
mm diameter bolts must be used to hold the cap on if the allowable stress in the bolts is 80 MPa, of which 55 MPa is the initial stress? What
circumferential stress is developed in the pipe?
a. 17 bolts, 75.3 MPa c. 18 bolts, 83.9 MPa
b. 19 bolts, 84.6 MPa d. 20 bolts, 85.2 MPa
a. 17 bolts, 75.3 MPa
The strength per foot of the longitudinal joint is 33 kips where as for
the girth joint it is 16 kips. Determine the maximum diameter of the
cylindrical tank if the internal pressure is 150 psi.
a. 34.66 in. c. 35.6 in
b. 36.66 in d. 37.6 in.
c. 35.6 in
A flexible shaft consists of a 0.20-in-diameter steel wire encased in a
stationary tube that fits closely enough to impose a frictional torque
of 0.50 lb·in/in.
Determine the maximum length of the shaft if the shearing stress is not to exceed 20 ksi.
a. 63 in c. 44 in
b. 21 in d. 50 in
What will be the angular deformation of one end relative to the other
end? G = 12 × 106 psi.
a. 20o c. 30o
b. 25o d. 35o
a. 63 in
c. 30o
A homogeneous cylinder 3 m in diameter and weighing 30 kN is
resting on two inclined planes at right angles with each other.
The inclined plane on the right side is 15 degrees from the
horizontal and the inclined plane at the left is 75 degrees from
the horizontal. If the angle of friction is 15° for all contact
surfaces.
What is the magnitude of the couple required to start the cylinder
rotating counterclockwise?
C. 14.76 kN-m
A 5-m steel shaft rotating at 2 Hz has
70 kW applied at a gear that is 2 m
from the left end where 20 kW are
removed. At the right end, 30 kW are
removed and another 20 kW leaves the
shaft at 1.5 m from the right end.
2. Find the uniform shaft diameter so
that the shearing stress will not
exceed 60 MPa.
a. 51.3mm
b. 58.7mm
c. 66.8mm
d. 69.6mm
d. 69.6mm
