A train w/ initial velocity of 80m/s has to stop at station 2km.ahead..what must the trains deceleration be?

Question

pls.help...thanks

Answer 1

v^2=u^2+2as

0=80^2+2*a*2000

solve for "a"

the negative value gotten implies decelaration

Answer 2

distance(s) = 2000m

initial velocity = 80m/s

final velocity would have to be zero since it comes to a stop

use this equation of motion:

v² = u² + 2as

0² = 80² + 2a(2000)

0 = 6400 + 4000a

a = 64/40

a = 1.6m/s²

It decelerates at 1.6m/s²

hope this helps^_^