I think it’s A, I’m so sorry if I’m wrong.
Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find
from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form
, which can be solved with the following formula:
(4)
Where:



Substituting the known values:
(5)
Solving (5) we find the positive result is:

A sound wave traveling eastward through air<span> causes the air molecules to Vibrate east and west. </span>
Answer: 60mph
Explanation:
Given the following :
First leg travel:
Distance = 30 miles
Time of travel= 30 minutes = 0.5 hour
Second leg travel:
Distance = 60 miles
Time of travel = one hour
Average speed :
Speed = total Distance / time of travel
Total distance in miles = (30 + 60) miles = 90 miles
Total time of travel = 1 hour + 0.5 hour = 1.5 hours
Average speed = total distance traveled / total travel time
Average speed = 90 miles / 1.5 hours
Average speed = 60 miles / hour
= 60mph
Lett me come back imma translate this... and then ill come to help