IB Physics IA help!

HELP!!!
I need to do my practice IA for next week and I need lab ideas. Does anyone have any ideas for mechanics or maybe waves that aren't too complicated?
Thank youu

Mechanics - rolling a marble ball down a ramp (Galileo's diluted gravity experiment), dropping a paper helicopter from various heights to calculate value of "g" on Earth, skateboard ramp, range of projectiles, use of ramp and force to move a car between two light gates

Waves - Adding weights to a spring to understanding how time period of oscillation is affected (Hooke's Law), how tension affects frequency of an oscillating string, silt experiment (understanding diffraction of light), length of string relation to the frequency of oscillation of a pendulum, other pendulum experiments, measuring light intensities (i.e. polarisation)

Feel free to pick one from the suggestions given....