Question

Your roommate (not an engineering major) decides to display his aquarium on a shelf mounted to the wall. Even though you offer to help him find and use the wall studs, he decides to use two plastic drywall inserts (one for each shelf mount) and attach the shelf to the drywall as shown below. The mass of the board he uses as a shelf is 1.25 kg, the aquarium has a mass of 2.00 kg and is the same width and length as the shelf, the shelf brackets are essentially weightless, and the information on the pack of drywall mounts claims that they can withstand a force of 59.5 N before they are pulled from the drywall. After getting the aquarium set up, your roommate runs a hose from the kitchen sink, starts to fill the aquarium, and you get all your books and papers off the floor. If water enters the tank at the rate of 0.23 kg/s, how long can water run into the tank before the drywall inserts fail?

Answer 1