Newton's first law of motion is connected with inertia :)
Answer:
a) 0.78 s
b) 58.86m/s'
c) Galileo's law of free fall
Explanation:
a) 
b)At the bottom:
kinetic energy = potential energy
downwards
c) Galileo's law of free fall says regardless of the masses, bodies in a vacuum will fall, on the earth, at the same acceleration
Since the position doesn't change over that time, it's zero
Answer:

Explanation:
<u>Average Speed
</u>
If an object travels a distance d in a time t regardless of the direction, the average speed is the quotient of the distance over the time:

It's known a person runs d=15 kilometers in t=2 hours, thus his/her average speed is:

Calculating:
