Question

Qual a energia cinética de uma partícula de massa 5000g cuja velocidade vale 72km/h? (1000g= 1kg ekm/h/3,6)

Answer 1

boa tarde

Ec= m . v² / 2
Ec = (5000/1000)Kg . (72/3,6)²m/s / 2
Ec = 5kg . 400 m/s / 2
Ec = 1000 kg.m/s
Ec = 1 KJ

espero ter ajudado

Answer 2

$\sf m=5000\,g$

$\sf m=5\,kg$

$\sf v=72\,km/h$

$\sf v=20\,m/s$

$\sf E_c=\dfrac{1}{2}\cdot m\cdot v^2$

$\sf E_c=\dfrac{1}{2}\cdot5\cdot20^2$

$\sf E_c=2{,}5\cdot400$

$\boxed{\boxed{\sf E_c=1000\,J}}$