<span>Your equation for the height of the stone at any time is h(t) = -16t2<span> + 128t + 32 .
From your equation, we can tell that you're defining the upward direction as
positive. We can also tell that you threw the stone upward, with an initial speed
as it left your hand of 128 feet per second, about 87 miles per hour ... a mighty toss indeed, and I think there's a man from the Chicago Cubs waiting outside
who'd like to talk to you.
Anyway, When the stone splashes into the water, h(t) = 0 .
</span></span>
<span>-16t²<span> + 128t + 32 = 0</span></span>
Divide each side by -16 :
t² - 8t - 2 = 0
I don't see any easy way to factor the expression on the left,
so I have to use the quadratic formula to solve this equation.
t = 4 plus and minus √18 .
t = +8.24 seconds
t = -0.24 second
Mathematically, both numbers are valid solutions.But when you apply
the equation to a real world situation, only the positive 't' makes sense.
So <u> t = 8.24 seconds</u>.
Its A
_______________________________________________________
Answer:
B is the right answer of the following statement
Velocity, unlike speed, includes a direction.
Velocity is a vector quantity which is defined by magnitude and direction.
Speed is a scalar quantity. It is the rate at which an object moves regardless of which direction.
Answer:
it would take rod B twice as much time
Explanation:
it would take rod B twice as much time as it is twice as thick and twice as long. Due to this reason it would take the electric charge not only more time but even more voltage to travel through the rod
