Respuesta :

K.E =   1/2mv²

4000 =   1/2 ˣ 80 ˣ  v²

4000 ˣ 2 = 80 v²

8000 = 80 v²

8000/ 80 =v²

100  = v²

Taking square root on b/s

√100 = √v²

10 = v

RELAXING NOICE
Relax