You walk into what looks like an ordinary elevator, holding your bathroom scale
ID: 1967613 • Letter: Y
Question
You walk into what looks like an ordinary elevator, holding your bathroom scale (as you do every morning), and press a random button. However, you should never have assumed that anything in Willy Wonka’s Chocolate Factory was ordinary. When you press the button, the doors swing closed and the elevator goes hurtling sideways. You jump in your surprise, and, to your even greater surprise, you don’t come back down, but are instead stuck to the wall of the elevator. The coefficient of static friction between you and the elevator wall is µs = 0.6.Question:What is the minimum horizontal acceleration of the elevator?
Explanation / Answer
Let the acceleration of the lift be a (sideways)
force of friction keep you from coming down, friction balances your weight.
friction =N , where N is the normal reaction to the surface
in this case the only horizontal force is due to the acceleration of lift sideways, so N = ma
friction = ma
this balances mg
ma= mg
a=g/ =9.8/0.6 =16.33m/s2