1.
The power that can be transmitted by a spindle of 55mm diameter running at
8000rpm and allowable stress of 5 mpa
2. A four-compression coil spring support one load of 400kg. All four spring are
arrange in parallel and rated same at 0.709kg/mm. Compute the deflection in mm
3. A 12cmx16cm air compressor is operating with a maximum pressure of 10kg/cm2.
There are 5 bolts with a yield stress of 64000psi which held the cylinder head to the
compressor. Determine the shearing stress of the bolts.
4. If the pitch of a screw is 2/9. Find the Thread per inch
5. A coil with spring constant of 1.75 KN/mm is elongated within the elastic range of
305 mm. The stored energy in N-m nearest to?
6. A steel shaft operates 150rad/s and must handle 2kw of power. The shearing stress
is not to exceed 40MN/m2. Calculate the minimum shaft diameter base on pure
torsion.
7. A rectangular key was used in a pulley connected to a line shaft with a power of 8kw
at a speed of 1200 rpm. If the shearing stress of the shaft and key are 30N/mm2 and
240N/mm2, respectively. What is the diameter of the shaft?
8. A rectangular key was used in a pulley connected to a line shaft with a power of
125kw at a speed of 900rpm. If the shearing stress of the shaft is 40N/mm2 and the
key to be 22N/mm2. Determine the length of the rectangular key if the width is one
fourth that of the shaft diameter
9. For a bolted connection specification suggest that a High-grade material 13mm bolt
be frighted to an initial tension of 55,000 N. What is the appropriate Tightening
torque?
10. A steel rod 75 inches long tested with a load of 3000 lb. is suspended from the
outer end. If the rod stretches 0.021in Find the modulus of elasticity of the steel if
rod diameter is 0.618
1. A 75 mm solid shaft is to be replaced with a hollow shaft of equal torsion strength.
Find percentage of weight saved if the outside diameter of the hollow shaft is 100
mm.
a) 57.39%
b) 67.31 %
c)48.49 %
d) 52.90%
2. A flange coupling is to be designed using 25 mm diameter bolts at a distance of 165
mm from the center of the shaft. Allowable shearing stress on the bolt in 103 MPa.
the shaft is to transmit 5,600 hp at a speed of 1200 rpm, how many bolts are needed
in the connection?
a) 2
b) 3
c) 4
d) 5
3. A keyed gears delivers a torque of 1000N-m thru its shaft 70 mm outside diameter. If
the key has thickness of 16mm and width of 14 mm, find the length of key. Assume
the permissible stress values of 60mpa for shear and 94 mpa in tension.
a) 43.45mm
b) 23.45mm
c) 34.24mm
d) 38mm
4. A turbine developing 15000hp turns the shaft at 300rpm. The propeller to this shaft
develops a thrust 150000lb. A hollow steel shaft having a outside diameter of 14in is
to be used. Determine the inside diameter of the shaft if the maximum stress based
on the torsion is not to exceed 7500 psi.
a) 9.59in
b) 8.76in
c) 10.59in
d) 11.34in
5. Three extension spring are hooked in series that support a single weight of 100kg.
The first spring is rated at 4kn/m and the other two springs are rated 6kn/m each.
Compute the equivalent stiffness of the three springs.
a) 1.71
b) 1.21
c) 1.51
d) 4.71
6. A line shaft is 2 15/16 inches in diameter and will transmit 50Hp when turning at
200rpm as constant rate. The shaft furnishes the power to 10 machines each
requiring 5hp to operate. Each of the 10 pulleys is keyed to the shaft by standard flat
key. If the width and thickness of the key are ¼ and ½ respectively. Find the length of
the key based on compression considering that the allowable compressive stress
for commercial shafting is 6000psi.
a) 0.326in
b) 0.357in
c) 0.2342in
d) 0.2252in
7. A flat key is to be designed for 75 mm diameter shaft which will transmit 150kw at
400 rpm. If allowable shearing stress is 200 mpa and key width is 15 mm, determine
the length of the key.
a) 30.65mm
b) 31.83mm
c) 33.75mm
d) 32.85mm
8. A 76.2 mm inside diameter shafting of SAE 1040 grade, cold rolled, having a yield
point of 50ksi and with a ¾ x 5 inches key. Compute the minimum yield point in the
key in order to transmit the torque to the shaft. The factor of safety to use is 2 and
Sys = 0.5Sy.
a) 39.12 ksi
b) 42.13 ksi
c) 279.20 ksi
d) 47.12 ksi
9. A cantilever of rectangular section is 100mm broad by 150mm deep and carries a
concentrated load of 15Kn at its free end. Neglecting the weight of the beam, find
the distance from the free end where the stress at the outer is 75MN/m2
a) 1.875m
b) 2.785m
c) 0.875m
d) 3.785m
