A steel rod 2 m long and 20 mm in diameter is placed inside a copper tube of 20 mm internal diameter and 30 mm external diameter. The tube and rod are rigidly joined at their ends and the tensile force of 50 kN is applied? What is the stress in the steel and copper. Es Steel = 200 GN/M2 Ec Copper = 110 Copper 41.3 Mpa; Copper 51.8 Mpa

One hazard of space travel is debris left by previous missions. there are several thousand masses large enough to detect by radar orbiting the earth, but there are far greater numbers of very small masses such as flakes of paint. calculate the force exerted by a 0.110 mg chip of paint that strikes a space shuttle window at a relative speed of 5.00 ✕ 103 m/s and sticks, given the collision lasts 6.00 ✕ 10-8 s. such a collision chipped the window of the ill-fated challenger in june 1983, causing $50,000 of damage.