Xiaoming and his classmates in the science and technology group made a parachute. They are going to explore this parachute with a 30-story building (the height of each floor is the same).

Experimental scheme:

(1) the time for the parachute to freely fall from the 30th floor balcony to the 10 floor balcony, to the 20th floor balcony and reach the ground, and record the measurement data;

(2) Repeat the above process twice;

③ Calculation speed.

record form

Other reasonable methods are also given points.

Therefore, the answer to this question is: tape measure, stopwatch; The parachute falls freely from the balcony on the 30th floor to the balcony on the 10 floor, to the balcony on the 20th floor and to the ground.