Question

Please answer 3 & 4.

3 : you may have noticed that concrete sidewalks have horizontal slits in-between each slab. you may have also noticed that bridges have metal grates located at different places along the road. these construction joints are related to thermal expansion. explain the connection !

4 : list one of example of condition , convection, and radiation .

Answer 1

4. A good example would be heating a tin can of water using a Bunsen burner. Initially the flame produces radiation which heats the tin can. The tin can then transfers heat to the water through conduction. The hot water then rises to the top, in the convection process.