A small toy cart equipped with a spring bumper rolls toward a wall with a speed of vv. The cart rebounds from the wall, with the same speed vv. The sketch below shows the initial velocity vector v⃗ iv→i, final velocity vector v⃗ fv→f, and the initial momentum vector p⃗ ip→i. Using the initial momentum vector as a basis, draw the change in momentum vector Δp⃗ Δp→ for the cart. You can obtain each vector's length and orientation by clicking on it to select it.

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explanation:

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.