PLZ HELP FASmartin throws a ball straight up in the air. the equation h(t)=-16t^2+40t+5 gives the height of the ball, in feet, t seconds after martin releses it. how many seconds before the ball martin threw hits the ground? AND SHOWWW WORKK

Given that Martin throws a ball straight up in the air.

The equation gives the height of the ball, in feet, t seconds after martin releases it.

We need to determine the time that it takes the ball to hit the ground.

Time taken:

To determine the time 't', let us equate h(t) = 0 in the equation

Thus, we have;

Switch sides, we get;

Now, we shall solve the equation using the quadratic formula.

Thus, we have;

Solving, we get,

Cancelling the common terms, we get,

Thus, the roots of the equation and

Simplifying the roots, we get,

  and  

  and  

Since, t cannot take negative values, then

Hence, It takes 2.6 seconds for the ball to hit the ground.

4a. is 3 miles every hour

4b. is 1/3 of an hour per mile

step-by-step explanation: