When rebuilding his car's engine, a mechanic must exert 300'N of force to insert a dry steel piston into a steel cylinder. What is the magnitude of the normal force between the piston and cylinder? (b) What is the magnitude of the force would he have to exert if the steel parts were oiled? (us for dry steel on steel = 0.6; µk for dry steel on steel = 0.3; us for oiled steel on steel = 0.05; µk for oiled steel on steel = 0.03)

only HANDWRITTEN answer needed ( NOT TYPED)

Calculate external support reactions, and the forces on the internal joints.

QUESTION 4 4.2 4.1 The ratio between the outside diameter and inside diameter of a pipe is 2,5 and the length is 400 mm, when the pipe is not subjected to any load. When a tensile load of 200 kN is applied to the pipe, its length increases by 0,195 mm. The Young's modulus of elasticity for a pipe is 188 GPa. Calculate the inside diameter and outside diameter of a pipe. The following results were obtained by means of a tensile test on a carbon steel specimen, having an original cross-sectional area of 20 mm² and the gauge length is 50 mm. Elastic limit load: Elongation at the elastic limit: =0,06125 mm =4 900 N Maximum load: =7 650 N Load at fracture: =5 050 N Elongation at failure: =15,2 mm Cross-section area at failure: 7,95 mm² Calculate the following: 4.2.1 The stress at the elastic limit. 4.2.2 The maximum stress. 4.2.3 The percentage elongation. 4.2.4 The percentage reduction in area.