You can see that if a was equal to g, your downward acceleration is that of gravity, namely the cable has snapped in the elevator, Then you don't feel any weight.

你会发现如果 a 等于 g,你下降的加速度就是重力加速度,也就是电梯的绳索断了,那时你会完全失重

耶鲁公开课 - 基础物理课程节选

"If you have to take Xanax to get on the elevator, you never learn that the elevator isn't something to be afraid of, " says Dr. Josephson.

WSJ: Anxiety Can Bring Out the Best

The summer months see Times Square overrun by visitors all scrambling for their "I Heart NYC" t-shirt and matching sun visor, while the Empire State Building's elevator queue can, through the heat-haze, seem to extend as far, horizontally, as the iconic building stretches for the skies.

BBC: Summer in the city: New York

While that might seem less than instant, it compares favorably with the alternative -- taking the elevator to the seventh floor, finding you car and then driving down endless ramps praying that your alloys don't make contact with the concrete skirts.

CNN: Valet parking, robot style