Problem_Solving_04

20問 • 1年前

問題一覧

A flywheel has a diameter of 1.5 m, and mass of 800 kg. What torque in N-m is needed to produce an angular acceleration of 100 revolutions per minute, per second?

D. 2356

A truck body lowers 5 in. when a load of 25000 lb is placed on it. What is the frequency of vibration in oscillations per second of the truck if the total spring borne weight is 40,000 lb?

C. 1.105

A 6 inches wide by 0.125 in thick. The cantilever is 30 inches long with 24 inches free length. Compute the spring thickness for minimum bending stress if E ═ 𝟒. 𝟓 × 𝟏𝟎𝟔 psi and axial load of 2500 lb per spring.

A. 1.5 cm

A flywheel weighing 457 kg has a radius of 375 mm. Compute how much energy, in N-m, does the flywheel loss from 3 rps to 2.8 rps?

B. 1474

How much work (J) is required to stretch a spring from a length of 0.05 m to 0.10 m if the unstressed length of the spring is 0.04 m? The stiffness is 10 kN/m.

A. 17.53

A cast iron flywheel pf 1 ft mean rim radius is rotating at a speed of 1200 rpm. If the weight of the rim is 30 lbs then calculate the centrifugal force.

C. 65.51 kN

A flywheel weighing 910 kg has a radius of gyration of 15.24 cm. The shaft journals are 30.48 cm in diameter and have a coefficient of friction of 0.06. After the wheel reaches 120 rpm, the driving force is withdrawn and the wheel slows down to 60 rpm. Calculate the lost energy of the wheel?

A. 125 kN-m

What is the line shaft diameter used to transmit 12 HP at 180 rpm with torsional deflection of 0.08 degrees per ft length?

C. 2.35 in

Calculate the maximum unit shear in a 3-inch diameter steel shafting that transmits 24000 in lb. of torque at 99 rpm.

A. 4530 psi

What is the power transmitted in HP by the shaft rotating at 1200 rpm and subjected to torsional moment of 1200 MN?

A. 202

How much torque in in-lb can be safely transmitted by a 7/16 in diameter shaft if safe stress is 7000 psi?

A. 4100 psi

Compute for the polar section modulus of an SAE 1060 shafting having a diameter of 3 inches. Use a factor of safety of 2 and design stress at 8000 psi.

D. 5.3

A rectangular key was used to connect the pulley connected to the lineshaft transmitting a power of 10 hp at a speed of 1200 rpm. What is the diameter of the shaft considering that the shearing stress of the shaft and key are 30 Mpa and 240 Mpa respectively?

C. 21.6 mm

A 16 ft steel lineshaft has no bending action except its own weight. What power (in Hp) can the shaft deliver at a speed of 200 rpm given that the torsional deflection will not exceed 0.008/ft of length?

D. 14.6

A hollow shaft has an inner diameter of 0.035 m and outer diameter of 0.06 m. Compute the polar moment of inertia of the hollow shaft.

D. 1.125 x 10^−6 m⁴

What is the torsional deflection in degrees of a 4.33 in. diameter, 1.4 meter long shaft subjected to ta twist moment of 3 x 106 N − mm? Note: The torsional modulus of elasticity is 83 Gpa.

C. 0.20

A 2 in. solid shaft is driven by a 36-in gear and transmits power at 120 rpm. If allowable shearing stress is 12 ksi, what horsepower can be transmitted?

B. 35.89

Compute the power that would a spindle 55 mm in diameter transmits at 480 rpm. Note: Stress allowed for short shaft is 59 Mpa.

D. 129.97 hp

What is the maximum unit shear in a 3-inch diameter steel shafting that transmits 24,000 in-lb of torque at 99 rpm?

B. 31.22 Mpa

Calculate the critical role for a W10 x 21 (𝐼 = 9.7 𝑖𝑛⁴) section acting as pinned column. The bar is 12 ft long and E ═ 30 𝑥 106 𝑝𝑠𝑖. Use Euler’s theory.

B. 138 kips

Machine Design ( 1st Set )

Jacky Shane Luyas Buhia · 20問 · 2年前

Machine Design ( 1st Set )