Algebra 2 Exam Review. !!!! PLEASE HELP I AM HOPELESS !!!

Question

A ball is thrown into the air with a velocity of 112 ft per second. The ball was released 6 feet above the ground. The height above the ground t seconds after release is modeled by h(t)=-16t^2 + 112t + 6.

 

a.) when will the ball reach 130 ft?

b.) will the ball ever reach 250 ft? explain.

c.) in how many seconds after its release will the ball hit the ground?

Answer 1

You're probably not hopeless, but you need to work on learning from examples & lectures & textbook.  That takes time; you're embedded in a time and culture in which thoughtfulness and quest for understanding are not encouraged.

 

Anyway, question (a)simply requires that you solve for h(t) = 130.  You can solve this quadratic equation by any convenient method learned in Algebra II.

 

(b) can be answered by seeing if the function's vertex has h(t)=250, using t = -b/(2a) for this quadratic function, whose graph is a downward-opening parabola.

 

(c) can be answered by setting h(t) = 0 and solving for t (positive solution).

 

I hope that you'll think about why these things are so.