To study how high a ball bounces, students drop the ball from various heights. The function h(t) = −16t2 + h0 gives the height (in feet) of the ball at time t measured in seconds since the ball was dropped from a height of h0. If the ball is dropped from a height of 10 feet, find the elapsed time until the ball hits the floor. Round to the nearest tenth.

sqrt(10/16)

Step-by-step explanation:

h0 is the height it was dropped from, and the question says we drop a ball from a height of 10, so we have h0 = 10.  

So now we have -16t^2 + 10 and we want to know when the height is 0, so when -16t^2 + 10 = 0.  So it's just algebra, and solving for t will give us the time.

-16t^2 + 10  = 0

-16t^2 = -10

t^2 = 10/16

t = sqrt(10/16)

Solving algebraically makes the negative an answe too, but you can't have a negative time.  Go ahead and plug in to double check though.  

the correct answer is c