Question

http://www.nysedregents.org/physics/611/physics-exam611.pdf Can someone help me on number 2? I've been trying to make sense of the units but I just can't make the answer end up to be in m/s/s/

Answer 1

Here, v = 15 metres/second = 15m/s
So, we know taht, v^2 - u^2 = 2as
Or, v^2 = 2as(since u = 0)
Or, 15*15 = 2 * a * 100
Or, 225 = 200a
Or, a = 225/200 = 9/8 = 1.125 m/s^2

Answer is option no. 2