For every action, the reaction is 1. equal and opposite in direction.
2. unequal and in the same direction.
3. unequal and opposite in direction.
4. equal and in the same direction.

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 

Since the pully is a simple machine so the mechanical advantage is a 1

It is the areas with lines. this may sound a little confusing, but i hope it !

I’m not sure about this question