• Consider a 20 meter long bridge, simply supported at each end.
• The primary beam for the bridge, which flexes upon loading, has a square cross section that is 30 cm on a side.
• This beam is made of concrete (which has a typical elastic modulus of 60 GPa)

When a car weighing 1000 kg is at the very center of the beam (and you can reasonably assume the entire load is applied just at the very center point), what will be the midpoint deflection of the beam (in cm)?

Remember F=ma, and a is gravitational acceleration. Watch your units.