A stone is thrown upward from ground level. The initial speed is 160 feet per second. (a) In how many seconds will the stone hit the ground?

Question

anonymous · Answer

http://answers.yahoo.com/question/index?qid=20081020202827AA3xeLr

anonymous · Answer

does not match with my answer choices

anonymous · Answer

lets calculate it

anonymous · Answer

the answers i am given are 16, 14,10,9,12

anonymous · Answer

a) i'm just gonna calculate the time it takes to reach the peak, and multiply that time by two, because the time going up will equal the time going down. 

(v0 = initial velocity BTW) 

v will be set to zero, because the only time velocity is 0 is when the projectile reaches its peak, which is what we want 

v = v0 + at 
0 = 160 + -32t 
-160 = -32t 
t = 5s 

takes 5s to go up. multiply by two, it will hit the ground in 10 seconds

anonymous · Answer

This is a physics problem. Post it in the Physics section and I'll be glad to help.

Also note that you'll need your kinematics equations for this.

@megumi

anonymous · Answer

Answer: 10 seconds

anonymous · Answer

10

anonymous · Answer

it is a Calculus problme

anonymous · Answer

|dw:1383279302811:dw|