To decrease the amount of time required to work without changing the total amount of work, you need

increase distance
increase power
decrease power
decrease distance

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 

The upward force acting on the wing of a airplane in flight is known as the "lift" force. (d)

The density of the block of iron is lees than the density of mercury but the density of the block of iron is greater than the density of water