An object is moving under a constant acceleration (never changes at any point). it is initially moving in the +x direction at 7 m/s. after some time the object stops and then starts moving in the -x direction. after a total time of 9 seconds, its average velocity for the entire trip is 8 m/s in the -x direction. how much distance does the object cover in this time in meters?

before we can answer, we have to see the choices that are printed there with the question.   that's the only way we can point you to the correct one.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.