An object is launched straight into the air. The projectile motion of the object can be modeled using h(t) = 96t – 16t2, where t is the time since launch and h(t) is the height in feet of the projectile after time t in seconds. When will the object be 144 feet in the air? When will the object hit the ground?

Respuesta :

Answer:

  • The object will be 144 feet in the air at t= 3 seconds
  • At t= 6 seconds, the object will hit the ground.

Step-by-step explanation:

We have been the model [tex]h(t) = 96t -16t^2[/tex]

Here.  t is the time since launch and h(t) is the height in feet of the projectile after time t in seconds.

For the height of the object to be 144 feet, we have

[tex]h(t)=144\\\\96t -16t^2=144\\\\16t^2-96t+144=0\\\\\text{Using the quadratic formula, we get}\\\\t_{1,\:2}=\frac{-\left(-96\right)\pm \sqrt{\left(-96\right)^2-4\cdot \:16\cdot \:144}}{2\cdot \:16}\\\\t_{1,\:2}=\frac{-\left(-96\right)\pm \sqrt{0}}{2\cdot \:16}\\\\t=3[/tex]

Therefore, after 3 seconds the object will be 144 feet in the air.

Now, when the object hits the ground then the height should be zero.

[tex]96t -16t^2=0\\16t(6-t)=0\\t=0,6[/tex]

Hence, at t= 6 seconds, the object will hit the ground.


Lanuel

a. The time at which this object would be 144 feet in the air is 3 seconds.

b. The time it would take this object to hit the ground is 6 seconds.

Given the following data:

  • Projectile motion = [tex]h(t) = 96t -16t^2[/tex]

Where:

  • t is the time measured in seconds.
  • h (t) is the height measured in feet of the projectile.

How to solve for time.

a. To determine when the object would be 144 feet in the air:

[tex]144 = 96t -16t^2\\\\16t^2-96t+144=0[/tex]

Dividing all through by 16, we have:

[tex]t^2-6t+9=0[/tex]

Solving the quadratic equation by factorization, we have:

[tex]t^2-3t-3t+9=0\\\\t(t-3)-3(t-3)=0[/tex]

t = 3 seconds.

b. To determine when the object would hit the ground:

Note: The object would would hit the ground when its height is zero (0).

[tex]96t-16t^2=0\\\\16(t-6)=0\\\\t-6=0[/tex]

t = 6 seconds.

Read more on time here: https://brainly.com/question/10545161