Mathematics: A stone is dropped from the top of a tower. The height h in meters from where the stone is dropped to the ground is given by the function h = -5t^2+ 10t + 40, where t is the time in seconds. How long does it take for the stone to touch the ground? F) 2 sec G) 3 sec H) 3.5 sec J) 4 sec pls i need help lol

A stone is dropped from the top of a tower. The

pamdhuber4224

28.06.2022

12 cm

Step-by-step explanation:

I don't think u have to use the phytagores theorem b/c the hypotenuse is 9+3=12. but if u have to use this.

${?a}^{2} + {b}^{2} = {c}^{2}$

${9}^{2} + {b}^{2} = {9 + 3}^{2}$

$81 + {b}^{2} = 9(9 + 3) + 3(9 + 3)$

$81 + {b}^{2} = 81 + 54 + 9$

$81 + {b}^{2} = 144$

${b}^{2} = 144 - 81 = 63$

${b}^{2} = \sqrt{53} = b = 7.93$

so if u found b then u can find c by using the same formula.

${a}^{2} + {b}^{2} = {c}^{2}$

${9}^{2} + {7.93}^{2} = {c}^{2}$

$81 + 63 = {c}^{2}$

${c}^{2} = 81 + 63 = 144$

$\sqrt{c} = \sqrt{144}$

c = 12

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