Answer:
0.5
Step-by-step explanation:
Answer: C.) 1.12 seconds
Step-by-step explanation:
Hi, to answer this question we have to substitute h=0 (when the rock hits the ground the height above it is 0) in the equation given:
h (t) = –16t2 + 20
Solving for t (time)
0= –16t2 + 20
16t2=20
t2=20/16
t=√1.25 =1.12 seconds (option C)
Feel free to ask for more if needed or if you did not understand something.
The answer is 1 6/25. This is in simplest form.
The projectile's horizontal and vertical positions at time 
are given by
where 
. Solve 
for the time it takes for the projectile to reach the ground:
In this time, the projectile will have traveled horizontally a distance of
The projectile's horizontal and vertical velocities are given by
At the time the projectile hits the ground, its velocity vector has horizontal component approx. 176.77 m/s and vertical component approx. -178.43 m/s, which corresponds to a speed of about 
.
12 miles - 132 minutes
1 mile - 132/12 = 11 minutes
66 miles = 11 x 66 = 726 minutes.
Hence your requires answer is 726 minutes.
Hope This Helps You!
