Evans wants to determine the effect of color on the temperature of the air inside of different colored boxes. He places white, black, and red boxes of the same size and material in the sunlight and a thermometer is placed inside each box. He observes and records the temperatures in the boxes at specific times throughout the day. What is the test variable (independent variable) in this investigation?

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