solve using the quadratic equation

Question

A projectile moves vertically upward such that its distant s(in feet) above the ground is given by s=200+150t-16t^2. Determine how high the projectile will go(to 3 significant digits).

Answer 1

The highest the projectile will go is when it reaches the vertex.

 

t at vertex: -b/2a = -150/(2(-16)) = 4.69 s

 

 

 

Use this time to find the height, s.

 

s = 200 + 150t - 16t² = 200 + 150(4.69) - 16(4.69)² = 552 ft