Because the propagation speed of electromagnetic waves is equal to the speed of light, the time required for electromagnetic waves to return from the moon to the earth is t = SV = 3.8×108m3×108m/s ≈1.27s;
(2) The gravity of the lunar rover on the horizontal lunar surface: g = mg×16 =140kg×10n/kg×16 ≈ 233.33N,
The pressure of the lunar rover on the lunar surface: F=G=233.33N,
The contact area between the lunar rover and the lunar surface: s = 6×10cm2 = 6×10-3m2,
The pressure of the lunar rover on the lunar surface;
p=FS=233.33N6× 10？ 3 m2≈38888.8 pa；
(3)① Measure the gravity of the object with a spring dynamometer;
Strike a match and explore whether there is air in space.
Answer: (1) electromagnetic wave; It takes 1.27 s for electromagnetic waves to return from the moon to the earth.
(2) The pressure of the lunar rover on the horizontal lunar surface is 38888.8Pa；;
(3)① Measure the gravity of the object with a spring dynamometer;
Strike a match and explore whether there is air in space.