Steel is an alloy of one of the main reasons steel is used more widely than iron is because it’ than iron.

iron and carbon, stronger.

Explanation: Steel is an alloy made by mixing iron with small quantities of carbon.  

Iron being a pure metal is malleable and brittle due to the presence of free electrons. The atoms of the metals can slip over one another due to these free electrons.

When carbon is added to iron, an alloy is formed and  becomes hard as presence of carbon do not allow the atoms  to move past one another. The tensile strength or resistance to break under applied force for steel gets more as compared to iron.

Thus steel is stronger as compared to iron.

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.