Doorstop#

Often a wedge-shaped doorstop won’t hold a door open unless you kick it until it sits tightly under the door.

Question Text#

What does forcing the wedge into a tight fit accomplish?

Answer Section#

Select all the choices that apply.

Note: You will be awarded full marks only if you select all the correct choices, and none of the incorrect choices. Choosing incorrect choices as well as not choosing correct choices will result in deductions.

  • Doing so increases the coefficient of friction.

  • Doing so increases the normal force between the floor and the bottom of the wedge.

  • In this position, moving the door INTO the wedge (to close it) will increase the static friction force between the wedge and the floor.

  • Doing so causes the friction to become kinetic friction instead of static friction.

  • Ghosts. It keeps ghosts from pushing the door shut.

Attribution#

Problem is licensed under the CC-BY-NC-SA 4.0 license.
The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.