Question

me ajudem por favor!!

Answer 1

Olá, Luiza.

$v = v_0 + at\Rightarrow 100=v_0+4a \Rightarrow v_0 = 100-4a\text{ (i)} \\\\ v^2=v_0^2+2a\Delta S \Rightarrow \\\\100^2=v_0^2 +2a\cdot320 \Rightarrow \\\\10.000=v_0^2+640a \Rightarrow \text{aplicando (i)}\\\\10.000=(100-4a)^2+640a\Rightarrow\\\\10.000=10000-800a+16a^2+640a\Rightarrow\\\\ 16a^2-160a=0\Rightarrow \\\\16a(a-10)=0\Rightarrow \\\\\boxed{a=10\,m/s\²}$

Resposta: letra "c"