Answer:
a. velocity
Explanation:
Slope is the time rate of change of position
The arrangements of the water molecules they begin to spread apart. As the water(ice) melts the molecules develop fewer compact and start juddering harder until the ice has changed state into liquid.
x=gt^2/2=>t^2=2x/g=30/9.81=3.05=>t=sqrt(3.05)=1.8 s
