Mechanics assignment

ENGR 201 Statics (100 points) Group Project

Objective:

a) Study the effect of floor surface roughness in statically stopping a door with spring loaded hinges by means of a doorstopper, while considering friction

b) find the amount of the internal forces inserted on the top hinge shafts

Project elements:

x The surface of the floor varies x The doorstopper’s material is rubber x The door is installed on the door jamb by three spring loaded hinges. Specification

of these two hinges is attached

x The specification of the door itself is provided within attached spec sheet

Description: find the sum of forces and moments of the door and its hinges (neglecting the friction in the hinges). This will involve summing the forces from the hinges and the

force of gravity. Since there are three hinges, there are three places where torque could

happen. We also need to find the frictional force that will put the door into equilibrium

when it hits the doorstopper. Then we have to find out which floor type provides a better

surface for use of a rubber doorstopper. The distance between the doorstop and the edge

of the door is for you to decide however you should keep it constant when switching

between different floors for sake of consistency of your result

Spec sheets:

x Door stop:

Length to peak point 4 3/4"

Width 2 1/8"

Height at peak point 1 1/4"

Color Black

Material Rubber

Mounting Location Floor Slide wedge under the door to hold it open.