-16t^2+64t=48

Question

a ball is thrown vertically upward with an initial velocity of 64 feet per second. solve the equation -16t^2+64t=48 to find the time t in seconds at which the ball is 48 feet from the ground

 

Answer 1

Cool so when you look at the equation given the first thing you do is factor

 

factor out -16t leaving you with

 

-16t(t-4)= 48

 

divide by -16 on both sides

 

t(t-4) = -3

 

t = -3 and t = 1

 

since t cannot be -3 seconds we rule out that solution and our answer is

 

t= 1 second.