Physics problem?

Question

An object is dropped from rest. 

 

a. 5 seconds later, what is it's speed?

 

b. At that point, what is the position with respect to the starting point?

Answer 1

a.

 

v(t) = gt in the downward direction, with g = 9.8 m/s²

 

v(5) =  (9.8 m/s²)(5s) = 49 m/s

 

b.

 

y = (1/2)gt² below the starting point

 

y(5) = (1/2)(9.8 m/s²)(5s)² = 122.5 m below the starting point