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Up and Down - help3

As a vertically-launched ball travels through the air it accelerates downward at all locations with a constant rate of acceleration of about -10 m/s/s (exactly -9.8 m/s/s). Like all accelerating objects, the ball's velocity will change. The velocity decreases as the ball rises towards its peak and increases as the ball falls downward from its peak. As in any situation, the direction of the velocity vector is in the direction that the ball is moving.

There are three very similar versions of this question. Each version displays a graphic of the trajectory of a vectically-launched ball with seven locations labeled on the graphic. In each version, you must rank the values of the velocity and the acceleration at three identified locations in order from smallest to largest.

Version 1
A ball is launched upward from the ground. The diagram shows the location of the ball at 1-second intervals. Rank the three indicated locations based on increasing ball speed and acceleration (magnitude only), beginning with the smallest.

Acceleration Magnitude

A free-falling object such as this one experiences an acceleration that is caused by gravity. This acceleration, caused by gravity, is sometimes referred to as the acceleration of gravity. Its value on Earth is 9.8 m/s/s and it is directed in the downward direction. Over the relatively short distance that this ball travels during its seven seconds, the value of the acceleration of gravity is not going to change. It remains as -9.8 m/s/s at all locations in this trajectory.

Velocity Magnitude

Free-falling objects like this one slow down as they move upward and speed up as they move downward. Since the rate of slowing down is equal to the rate of speeding up, one can reason that it is the nearness (or far-ness) from the peak location that determines the relative speed. The speed at the peak location is 0 m/s; and the closer the ball is to this location, the closer that the speed is to 0 m/s. Similarly, the further that the ball is from this peak location, the further that the speed value is from 0 m/s. Use this information to rank the ball's speed at the three indicated locations.

Try this link to The Physics Classroom Tutorial for more help with the motion of free-falling objects:

Introduction to Free Fall

The Acceleration of Gravity

How Fast? How Far?