A basketball has a positive or negative a acceleration when thrown

A negative acceleration

Explanation:

When thrown, the basketball leaves the hands of the thrower with an initial velocity. This initial velocity is then gradually decelerated (negative acceleration) by drag forces, and its gravitational attraction to the earth, until the ball comes to rest. The acceleration on a thrown basketball is therefore negative.

that would be b i just took the test : )

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )