A rock is dropped from a height of 60 m and is in free fall. What is the velocity of the rock as it reaches the ground 3.5 seconds later?
3 answers
20 m/s downward
v=gt=9.8 x 3.5 =34.3 m/s
Vf=Vi+gt
Vf= final velocity (what we're solving for)
Vi= initial velocity (in our problem, initial velocity is zero because the rock starts from rest)
g=gravitational acceleration (9.8m/s/s)
t= time (in our case, 3.5s)
Vf= 0m/s + (9.8m/s/s)(3.5s)
Vf= 34.3m/s downward (you must have the direction because velocity is a vector quantitiy, meaning that it is represented by both magnitude and direction)
(source AP physics B)
Vf= final velocity (what we're solving for)
Vi= initial velocity (in our problem, initial velocity is zero because the rock starts from rest)
g=gravitational acceleration (9.8m/s/s)
t= time (in our case, 3.5s)
Vf= 0m/s + (9.8m/s/s)(3.5s)
Vf= 34.3m/s downward (you must have the direction because velocity is a vector quantitiy, meaning that it is represented by both magnitude and direction)
(source AP physics B)