A roller coaster is moving at 25 m/s at the bottom of a hill. Three seconds later it reaches the top of the hill moving at 10 m/s. What was the acceleration of the coaster?

1 Answer
Nov 22, 2016

#-5m//s^2#

Explanation:

#a_(avg)=(Deltav)/(Deltat)=(v_f-v_i)/(t_f-t_i)#

Where:-

#v_f# is the final velocity
#v_i# is the initial velocity
#t_f# is the final time
#t_i# is the initial time

The final velocity of the roller coaster is #10m//s# (when it reached the top"#t=3s#"), and the initial velocity is #25m//s# (when it started moving at the bottom "#t=0s#")

So
#v_f=10m//s#
#v_i=25m//s#
#t_f=3s#
#t_i=0s#

#a_(avg)=(10-25)/(3-0)=-15/3=-5m//s^2#