Usingthe quadratic formula computethetime it takes a ball fi

Usingthe quadratic formula, computethetime it takes a ball fired upwards at 433m/s, from the ground, to reach 647 m for the second time . give answer to decimal places

Solution

Usingthe quadratic formula, compute thetime it takes a ball fired upwards at 433m/s, from the ground, to reach 647 m for the second time

H(t) = h0 + u*t -(1/2gt^2)

ho =0

So, H(t) = u*t - (1/2)gt^2

= 433t -(9.81)/2t^2 = 433t - 4.9t^2

h(t) = 647 mt

647 = 433t - 4.9t^2

433t - 4.9t^2 - 647 =0

Solve the quadratic equation to get t:

t = ( -b + /- sqrt(b^2 -4ac)/2a

t= 1.52 sec

t = 86.85 sec

We have two values:

So, t= 1.52 sec , this is the first time ball reaches 647mt

then after t = 86.85 sec second time ball reaches 647 mt height

So, Solution t = 86.85sec