Mechanics | Relativity Answers

(3) A 20 cm long steel tube of 15 cm internal diameter and 1.0cm thickness is surrounded by a brass tube of the same length and thickness. The tubes carry an axial load of 150 kN. Estimate the load carried by each.
Es = 21 x 106 N/cm2 Eb = 10 x 106 N/cm2.

solid shaft of 10cm diameter transmits 74 kW at 150 rev/min. Calculate (a) the torque on the shaft, (b) the maximum shear stress developed, (c) the angle of twist in a length of 1.50m, and (d) the shear stress at a radius of 3cm. Take G = 8 MN/cm2.

) A steel shaft ABCD having a total length of 3.5 m consists of three lengths having different sections as follows: AB is hollow having outside and inside diameters of 100 mm and 62.5 mm respectively, and BC and CD are solid. BC has a diameter of 100 mm and CD has a diameter of 87.5 mm. If the angle of twist is the same for each section, determine the length of each section. Find the value of the applied torque and the total angle of twist, if the maximum shear stress in the hollow portion is 47.5 MPa and shear modulus, C = 82.5 GPa. (Assuming the torque T and shear modulus are the same for all the sections).

Determine the maximum uniformly distributed load, a simply supported 40cm deep and 20cm wide timber beam can carry over a span of 4m. The maximum permissible bending stress for the timber is 2N/mm

A 25mm wide and 100mm deep beam is 3.4m long. It carries a load of 1500N at the middle. Determine the maximum stresses due to bending.

(1) A rectangular block of metal of 50 mm x 25 mm cross-section and 125 mm length carries a tensile load of 100 kN along its length, a compressive load of 1.0 MN on its 50 x 125 mm faces and a tensile load of 400 kN on its 25 x 125 mm faces. If E = 208 GN/m² and Poisson’s ratio = 0.3, Find (a) change in volume of bar (b) increase required in 1.0 MN load to produce no change in volume.

A mild steel bar of 2.0cm diameter is subjected to a tensile test. The bar yields under a load of 80kN. It reaches a maximum load of 150kN and breaks finally at a load of 70kN. Estimate the.(a) Average tensile stress at the yield point. (b) Ultimate tensile stress. (c) Average stress at the bearing point if the diameter of the fractured neck is 1cm.

A particle is traveling along a straight path described as = 0.75x. If its position along the x-axis is x=(8t)m, where t is in seconds, determine its speed when t=2s.

A 1kg ball is connected to a rigid rod with negligible mass. If it is released from at the position shown, determine its speed when the rod becomes vertical. The spring is initially unstretched and has a spring constant k=4N/m.

Determine the coefficient of restitution e between ball A and ball B the velocities of A and B before and after collision are shown. A=8m/s moving forward and B=2m/s moving backward before collision and A=1m/s moving forward and B=9m/s moving forward after collision.