Sign In
Plot the graph of the given quadratic function.
Find the t-coordinate of the vertex.
Use the answer from Part B.
About 479.52 meters
About 5.71 seconds
About 11.42 seconds
The rocket's height h in meters is given by the equation h=- 4.9t^2+56t, where t is the time in seconds after the launch. Let's plot the parabola h=- 4.9 t^2+56t.
We are asked to find the maximum height the rocket will reach. Since the parabola open downwards, the maximal value is at the vertex. First, we will find the t-coordinate of the vertex, p.
a= - 4.9, b= 56
Multiply
- a/- b=a/b
Calculate quotient & Use a calculator
Next, we will find the maximal value of h by substituting 5.71 for t into the formula for h.
t= 5.71
Calculate power
Multiply
Add terms
Round to 2 decimal place(s)
Therefore, the maximum height the rocket will reach is about 479.52 meters.
We are asked to find the time that the rocket will reach its maximum height. From Part A we know that this is p≈ 5.71 seconds.
From Part B we know that after about 5.71 seconds the rocket will reach its maximum height from the ground level. Therefore, after another 5.71 seconds the rocket will reach the ground level. Therefore the rocket will land after about 5.71+5.71=11.42 seconds.