in the middle of math class, maxs pencil rolls off of his desk and onto the ground 2.5 feet below. which…

in the middle of math class, maxs pencil rolls off of his desk and onto the ground 2.5 feet below. which equation can you use to find how many seconds it takes for the pencil to hit the ground? if an object falls from s feet above the ground, the objects height in feet, h, after t seconds can be modeled by the formula h = -16t² + s. 0 = -16t² + 2.5 0 = -16t² + 2.5t to the nearest tenth of a second, how long does it take for the pencil to hit the ground? seconds

in the middle of math class, maxs pencil rolls off of his desk and onto the ground 2.5 feet below. which equation can you use to find how many seconds it takes for the pencil to hit the ground? if an object falls from s feet above the ground, the objects height in feet, h, after t seconds can be modeled by the formula h = -16t² + s. 0 = -16t² + 2.5 0 = -16t² + 2.5t to the nearest tenth of a second, how long does it take for the pencil to hit the ground? seconds

Answer

Answer:

  1. Equation: $0=-16t^{2}+2.5$
  2. Time: $0.4$

Explanation:

Step1: Select the correct equation

The height - formula is $h = - 16t^{2}+s$. When the pencil hits the ground, $h = 0$ and $s = 2.5$. So the equation is $0=-16t^{2}+2.5$.

Step2: Solve the equation for $t$

First, rewrite the equation as $16t^{2}=2.5$. Then $t^{2}=\frac{2.5}{16}=0.15625$. Taking the square - root of both sides, $t=\sqrt{0.15625}\approx0.4$ (we consider the positive value of $t$ since time cannot be negative).