Ahelical compression spring is required to provide a minimum force of 80 n at installation and have a working deflection of 25 mm. the spring rate is 35 n/mm. the coil must fit in a 50 mm diameter hole with 2.5 mm clearance. the spring has squared and ground ends and is made from astm a227 4.0 mm diameter wire, without presetting. using a 15% clash allowance, find: - (i) the number of coils required; and (ii)the free length of the spring.

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Afour cylinder four-stroke in-line engine has a stroke of 160mm, connecting rod length of 150mm, a reciprocating mass of 3kg and its firing order is 1-3-4-2. the spacing between cylinders is 100mm. i. show that the engine is in balance with regard to the primary inertia forces and primary 3. a and secondary inertia couples. li determine the out of balance secondary inertia force ii. propose ways of balancing this out of balance force and discuss the challenges that will arise