My question is the highlighted one

48) When listening to the astronauts, they said when they were moving at a constant speed of 18,000 miles/hour in dark space, they felt like they were standing still. Why? 49) Sticking a paperclip in a 110 Volt outlet can be dangerous yet when I touch a door knob get shocked releasing 50,000 volts, it is quite harmless. Why? 50) If a heavy & a light person jump off a high building on earth, who hits the ground first? How is this different on the moon & why