A145 g baseball is dropped from a tree 13.0 m above the ground. (a) with what speed would it hit the ground if air resistance was negligible? (b) if it actually hits the ground with a speed of 8.00 m/s, what is the average force of air resistance exerted on it?

a)  V = 15.96 m/s

b)  F = 1.06 N

Explanation:

a)  Using the conservation of energy:

so:

where m is the mass, g the gravity, h the altitude and v the velocity when the baseball hit the ground. So, replacing values:

solving for v:

v = 15.96 m/s

b) If there are air resistance:

so:

Where F is the average force and d the distance of fall.

so, replacing the values:

Solving for F:

F = 1.06 N