Why do thicker lubricating oils have higher melting points?
a. they have longer chains of carbons.
b. higher density always means higher melting point.
c. unsaturated hydrocarbons have a higher density than saturated hydrocarbons.
d. thicker oils are more solid than liquid, so they have another phase change to complete

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Ai think hope that