1. The problem statement, all variables and given/known data A basketball star covers 2.80m horizontally in a jump to dunk the ball. His motion through space can be modeled as that of a particle at his center of mass. His center of mass is at elevation 1.02m when he leaves the floor. It reaches a maximum height of 1.85m above the floor and is at an elevation of 0.900m when he touches down again. Determine his time of flight. So I am using: Yi = 1.02m Ymax = 1.85m Yf= 0.900m R= 2.80m 2. Relevant equations Vx=Vosin(theta) Vy=Vocos(theta) x=Vocos(theta)t y=Vosin(theta)t-(1/2)gt^2 R=(Vo^2 sin(2theta))/g Rmax=(Vo^2)/g t=(2Vosin(theta))/g Ymax=(Vo^2sin^2(theta))/(2g) Yf=Yi + Vyo*t - (1/2)gt^2 3. The attempt at a solution Not being given Vo or theta I am having trouble finding an equation that works. Here is what I am thinking: Start at Ymax since Vyo=0 and go to Yf Yf=Yi + Vyo*t - (1/2)gt^2 0.90m=1.85m-(1/2)gt^2 -0.95m=-(1/2)gt^2 1.90m=gt^2 t=sqrt(1.90m/9.80(m/s^2)) t1=0.440s Then start at Ymax and go to Yi Yf=Yi + Vyo*t - (1/2)gt^2 1.02m=1.85m-(1/2)gt^2 -0.83m=-(1/2)gt^2 1.66m=gt^2 t=sqrt(1.66m/9.80(m/s^2)) t2=0.412s t1+t2=t 0.440s+0.412s=0.852 Which seems too short, but maybe not. Any help is appreciated.