Question

Need help with number 6. Also could you tell me if I did number 5 right? Thanks

Answer 1

Check the picture below.

thus

$\bf \stackrel{0}{h}=-16t^2+64\implies 0=-16t^2+64\implies 16t^2=64\implies t^2=\cfrac{64}{16} \\\\\\ t^2=4\implies t=\sqrt{4}\implies t=\stackrel{seconds}{2}$

as far as 5, is correct, however

$\bf \textit{using the pythagorean theorem}\\\\ c^2=a^2+b^2\implies c=\sqrt{a^2+b^2}\qquad \begin{cases} c=hypotenuse\\ a=adjacent\\ b=opposite\\ \end{cases} \\\\\\ c=\sqrt{15^2+8^2}\implies c=\sqrt{289}\implies c=17$