Respuesta :

h0=6.5
h(t)=-16t²+vt+6.5

when h(3.5)=5
so
5=-16(3.5)²+3.5v+6.5
5=-16(12.25)+3.5v+6.5
5=-196+3.5v+6.5
5=-189.5+3.5v
194.5=3.5v
389/7=v≈55.5714