Gravity affet everything and it touches nothing.
Hope this helps!
Answer:
for every action thete is an equal and opposite reaction
Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8 
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0 
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2 
Answer:
wish I could help
Explanation:
I been rereading this and I can't solve it lemme go ask people in ma house real quick