A train w/ an initial velocity of 80m/s2? how much time does it takes to reach a velocity of 24m/s from rest?

Question

pls. i need your guide .......more thanks!!

Answer 1

I am assuming you meant a train with initial acceleration of 800 m/s^2, because initial velocity is zero if starting from rest.

vf - final velocity = 24 m/s

vo - initial velocity = 0 m/s

a - acceleration = 80 m/s^2

t - time

vf=vo + at

at = vf - vo

t = (vf - vo)/a

t = (24-0)/80 = .3 s

Answer 2

well I think that the 80m/s2 is the acceleration I don't know why it said initial velocity and also said from rest?

so for me

vf is final velocity

vi is initial velocity

a is acceleration

t is time

a= 80m/s2

vf= 24m/s

vi= 0 (because it said from rest)

t= ?

t= (vf- vi)/a

/ is divide

t= (24- 0)/80

t= 24/80

t= 0.3 seconds

check...

a= (vf- vi)/t right?

ok

a= (24- 0)/0.3

a= 24/ 0.3

a= 80m/s2

uhm.. ok?