3.A bridge usually has expansion joints. They allow the bridge to become slightly longer when it experiences thermal expansion. Look at the diagram below of the bridge joint. When the weather
becomes cool, the "teeth" of the joint move away from each other. When the weather becomes
warm, they move toward each other. Which statement is true about the particles that make up the
bridge?
A. When the sides of the joint are close together, the particles have more kinetic energy
than they do when the sides are farther apart.
B. When the sides of the joint are far apart, the particles have more kinetic energy than
they do when the sides are closer together.
C. The particles contain the same amount of kinetic energy no matter how much the
bridge has expanded.
D. The kinetic energy of the particles changes, but the amount it changes does not
depend on the temperature of the bridge.