Quadratic & Exponential Functions

Question

An object is launched at 17.2 m/s from a 25-meter tall platform. The equation for the object's height h at time t seconds after launch is: h(t) = -4.9t^2 + 17.2t +25, where h is in meters.

a. Graph this equation.
b. When does the object strike the ground?

Answer 1

(a) This forum does not support graphing too well.

(b) Set h(t)=0 and solve the resulting quadratic equation for t using the quadratic formula. You will get a negative and a positive solution. Since t starts at t=0, the positive solution is the correct one.