Suppose 1 = 19hz and 2 = 21hz. what are the first two times where the slowly oscillating
trig function has a value of zero? these will be two times where the sound intensity is at a
minimum.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? 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