Equation of motion

A ball is dropped from an initial height of 1.2m. After hitting the ground the ball rebounds to a height of 0.8m. The ball is in contact with the ground for 0.16s. Using the acceleration of free fall calculate:
a) the speed of the ball immediately before hitting the ground, am I right in saying that s=1.2, u=0, a=-9.81
b) the speed of the ball immediately after hitting the ground - for this one I don't know which values fit in suvat
c) the acceleration of the ball while it is in contact with the contact with the ground, would this be 9.81 and positive

A ball is dropped from an initial height of 1.2m. After hitting the ground the ball rebounds to a height of 0.8m. The ball is in contact with the ground for 0.16s. Using the acceleration of free fall calculate:
a) the speed of the ball immediately before hitting the ground, am I right in saying that s=1.2, u=0, a=-9.81
b) the speed of the ball immediately after hitting the ground - for this one I don't know which values fit in suvat
c) the acceleration of the ball while it is in contact with the contact with the ground, would this be 9.81 and positive

well it's interested in speed rather than velocity so you don't need to worry too much about your sign convention as you just need the magnitude.

b/ at maximum height it should be fairly clear that vertical velocity is zero - this is your final velocity. s is 0.8m

c/ likely to be higher than 9.81 since the ball needs to slow down to a stop from your first speed result and then accelerate up to your second speed result in the opposite direction... all in a comparatively short time.

So for c would s=0, u=be the velocity before ground and v=be the velocity after ground and t be 16