Question

Um corpo de massa 3kg passa de 10m/s para 20m/s. determine a variação de energia cinética sofrida pelo corpo

Answer 1

ΔEc = Ecf - Eci
ΔEc = 3(20)^2/ 2 - 3(10)^2/2
ΔEc = 600 - 150
ΔEc = 450J

Answer 2

$Ola'~~~\mathbb{MATEUS} \\ \\ Variac\~ao~de~energia~ cin\acute{e}tica ~e':~~\boxed{\triangle_{E_c}=E_{C_f}-E_{C_i}} \\ \\ E~energia~cin\acute{e}tica~e'~~\boxed{E_c= \frac{m.v\²}{2}} \\ \\ent\~ao: \\ \\ \triangle_{E_c}= \frac{3.(20)\²}{2}- \frac{3.(10)\²}{2}~~---\ \textgreater \ desenvolvendo~temos: \\ \\ \triangle_{E_c}=\underbrace{600-150 }_{450} \\ \\\boxed{ \boxed{\triangle{E_c}=450J }}$

$\mathbb{ttttttttttttttttttttttttttttttttttt} \\ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Espero~ter~ajudado!!$