What is an object's acceleration if it is moving at 30 m/s and comes to a stop in 5 s?

1 Answer
Oct 25, 2016

The object's acceleration is #"-6 m/s"^2"#.

Explanation:

Remember:
#a = (∆v)/(∆t)#
and

#∆v = v_f - v_i#

So, in this case:
#v_i = "30 m/s"# [fwd]
#v_f = "0 m/s"# (it comes to a stop)
#∆t = 5s#

Thus,
#a = (∆v)/(∆t)#

#a = (v_f - v_i)/(∆t)#

#a = (-30 m/s)/("5s")#

#a = "-6 m/s/s" or "-6 m/s"^2"#