You throw a ball at a height of 5 feet above the ground. The height h (in feet) of the ball after t seconds can be modeled by the equation h=-16tsqaured +44t +5
A. After how many seconds does the ball reach a height of 15 feet?
B. After how many seconds does the ball hit the ground? Round your answer
to two decimal places.

Factor this polynomial completely x^2-64

I’m still confused on how to work the percentages

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?