Arock is thrown upward from the level ground in such a way that the maximum height of its flight is equal to its horizontal range r.
(a) at what angle θ is the rock thrown? °
(b) in terms of its original range r, what is the range rmax the rock can attain if it is launched at the same speed but at the optimal angle for maximum range? rmax =
(c) would your answer to part (a) be different if the rock is thrown with the same speed on a different planet? yes no

Answer

a) For the rock

b) for maximum range

c) The value of θ is the same on every planet as g divides out.

double the distance = divide strength by 4

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.