Question

The graph below shows the height of a projectile t seconds after it is launched. If acceleration due to gravity is –16 ft/s2, which equation models the height of the projectile correctly?

h(t) = at2 + vt + h0

mc012-1.jpg
h(t) = –16t2 + 42t + 5
h(t) = –16t2 + 5
h(t) = –16t2 + 32
h(t) = –16t2 + 32t + 5

Answer 1

Use h(t) = -16t^2 + vt + h0. From the graph h(0)=5 so h0=5. The graph shows h(1)=21, so -16(1)^2 + v(1) + 5 = 21 → -16 + v + 5 = 21 → v = 32.

Thus h(t) = -16t^2 + 32t + 5.