a skydiver drops her watch as she jumps out o...

a skydiver drops her watch as she jumps out of a plane flying at an altitude of 6,400 feet. if the equation for height as a function of time is h(t)= -16t² + initial height where t is time in seconds and h(t) is height in feet, how many seconds will it take for the watch to hit the ground? ? seconds

Answer

# Explanation: ## Step1: Set up the equation When the watch hits the ground, $h(t)=0$. The initial - height is 6400 feet. So the equation becomes $0=-16t^{2}+6400$. ## Step2: Rearrange the equation Add $16t^{2}$ to both sides of the equation: $16t^{2}=6400$. ## Step3: Solve for $t^{2}$ Divide both sides of the equation by 16: $t^{2}=\frac{6400}{16}=400$. ## Step4: Solve for $t$ Take the square - root of both sides. Since $t$ represents time, we consider the positive square root. So $t = \sqrt{400}=20$. # Answer: 20