A stone falls freely from rest for 8.0 s. a. Calculate the stone's velocity after 8.0 s.
b. What is the stone's displacement during
this time?

a) The acceleration that the stone has is the gravitational acceleration and it is always the same (Actually not but assumed to be so)

The gravitational acceleration is 9.81 m/s²

Since this acceleration is always constant, we can use the formula of V = g × t, where V is velocity, g is the gravitational acceleration and t is time.

Let's use this formula: V = g × t = 9.81 × 8.0 = 78.48 m/s

b) Displacement in free falls is calculated by the formula of d = 1/2 × g × t², which is actually derivated from average velocity.

If we use the formula, d = 1/2 × 9.81 × 8² = is found to be 313.92 m

If there is anything you do not understand or anything is wrong, please let me know and I am sorry for my bad English ^^