The graph shows the acceleration of the cart with three
different fan speeds. the fan provides the force
necessary to accelerate the cart.
as the fan speed increases, the acceleration of the cart
the type of relationship that exists between the force
applied to the cart by the fan and the acceleration of
the cart is
relationship.

Explanation:

We know that the rate of change of velocity is called acceleration of an object. Its expression is given by :

The force acting on an object is the product of mass and acceleration. It is given by :

F = ma

It is clear that as the fan speed increases, the acceleration of the cart increases. Also from the Newton's second law of motion, the force  applied to the cart by the fan and the acceleration of the cart has direct relationship.

v 154.9= 0.9 length length s little over 154.9cm

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.