Hi Riley,
If no one catches the shirt and it falls to the ground, that makes h 0, so:
0= -16t2 + 96t + 4
Now, we can solve this using the quadratic formula:
x= [-b +/- sqrt(b2-4ac)]/2a
a= -16
b= 96
c=4
x= [-96 +/- sqrt(962-4(-16)(4))]/(2(-16))
Now, you will get two answers for x, one when you add the -96 and one when you subtract the negative 96.
x1= -0.041 seconds
This makes sense as it represents the point in time BEFORE the t-shirt was launched. It's approximately 0.
x2= 6.04 seconds, the correct answer, the point where the ball completes its parabolic arc and hits the ground.