From the edge of a rooftop, you toss a green ball upward with an initial velocity of 10 m/s and a blue ball downwards with the same initial speed. air resistance is negligible. when they reach the ground below
a. the green ball will be moving faster than the blue ball.
b. the blue ball will be moving faster than the green ball.
c. the two balls will have the same speed.

c.The two balls will have the same speed.

Explanation:

When two balls green and blue both are moving with initial velocity 10m/s.

The green ball has been tossed  upward and blue ball downwards.

Air resistance is negligible means there is no force which oppose the motion of balls.

When blue balls has been tossed downward then the blue ball will move under the gravity.

When green fall downward then the ball falls under the gravity because there is no air resistance.

Therefore, both balls move with acceleration due to gravity when they wil reach at ground.

Therefore, the velocity of both balls are same.

Hence, the two balls will have the same speed.

Option c is true.

temp rises, and expansion

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.