Question

Recall that the height of an object t seconds after it begins moving when gravity is the only force acting on the object is given. h(t)=-16x^2 + v0t + h0. h(t) is given in feet. v0 = initial velocity of object in ft/sec. ho= initial height of object in feet. If the feather is dropped from the top of the bridge 90 feet above a river, how long does it take the feather to reach the water?

Answer 1

That's pretty easy, have a look :

$h(t)=−16x2=v0t+h0$
$v0=0 ft/sec$
$h0=90 ft$

The only thing you need to do is to find t and the problem is solved.

Answer 2

Answer:

Time taken, t = 2.37 seconds

Explanation:

It is given that,

Height of an object at time t is given by :

$h(t)=-16t^2+v_0t+h_0$

Where

v₀ is initial velocity of object

h₀ is initial height of the object

The feather is dropped from the top of the bridge 90 feet above a river. we have to find the time taken by the feather to reach the water.

At the surface of water, h(t) = 0 and v₀t = 0

So, $0=-16t^2+0+90$

t = 2.37 seconds

The feather will take 2.37 seconds to reach the water surface.