Solve the problem.
-If a rocket is propelled upward from ground level, its height in meters after t seconds is given by h = -9.8t2 + 78.4t. During what interval of time will the rocket be higher than 147 m?
A) 0

Question

Solve the problem.
-If a rocket is propelled upward from ground level, its height in meters after t seconds is given by h = -9.8t2 + 78.4t. During what interval of time will the rocket be higher than 147 m?
A) 0 < t < 3
B) 3 < t < 5
C) 5 < t < 6
D) 6 < t < 8

Quizplus · Accepted Answer

To find when the rocket will be higher than 147 m, we set the height equation greater than 147 and solve for t: -9.8t^2 + 78.4t > 147. Rearranging gives a quadratic equation: -9.8t^2 + 78.4t - 147 > 0. Solving this quadratic equation for t will give the interval during which the rocket's height exceeds 147 m. The correct interval is between 3 and 5 seconds.

Solve the Problem. -If a Rocket Is Propelled Upward from Ground Level, Its