SOLUTION: I've heard that tossing a coin into a fountain will bring me good luck, so I throw a silver dollar up with a velocity of 5m/sec. and it falls into the fountain 1.3 meters below my
Question 338999: I've heard that tossing a coin into a fountain will bring me good luck, so I throw a silver dollar up with a velocity of 5m/sec. and it falls into the fountain 1.3 meters below my hand. How long is the coin in the air?
In this question i just really dont understand how to do quadratic equations when you dont have the acceleration unless its -9.8m/s squared, but really not sure. Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! I've heard that tossing a coin into a fountain will bring me good luck, so I throw a silver dollar up with a velocity of 5m/sec. and it falls into the fountain 1.3 meters below my hand. How long is the coin in the air?
In this question i just really dont understand how to do quadratic equations when you dont have the acceleration unless its -9.8m/s squared, but really not sure.
.
Yes, gravity is your acceleration.
.
Applying the equation of motion:
h(t) = (1/2)gt + vt + vo
where
h(t) is height
g is gravity
v is initial velocity
t is time
vo is the initial height
.
h(t) = (1/2)(-9.8)t + 5t + 1.3
h(t) = -4.6t + 5t + 1.3
.
set h(t) to zero and solve for t:
0 = -4.6t + 5t + 1.3
applying quadratic formula we get:
t = {-0.217, 1.304}
we can throw out the negative solution leaving:
t = 1.3 seconds
.
Details of quadratic to follow:
