Thermal Expansion HW1

What is Thermal expansion?

• The transfer of thermal energy between materials by the collisions of particles 
• Is a decrease in a materials volume when temperature decreases 
• An increase in a materials volume when temperature increases
• Chicken fried rice

Objects gain heat and _________. 

• expand
• contract

When temperature increases, distance between molecules ______________.

• decreases

• increases

• stays the same

What happens to the molecules of a solid when it is heated?

• Slow down
• Speed up
• Don't change speed
• Shrink

What happens to the molecules of a solid when it is heated?

• Slow down
• Speed up
• Don't change speed
• Shrink

Choose the symbol which denotes the 'coefficient of expansion'

• θ
• ρ
• Σ
• α

What does the following symbol 'Δ' denote?

• Sum of
• Coefficient of Expansion
• Change in
• Temperature

Select the correct formula to calculate linear change in length...

• ΔL = LαΔT
• ΔT = ΔL/Lα
• σ = F/A
• ε = ΔL/L

Calculate the change in length of a 100mm aluminium bar that has increased in temperature by 55⁰C.  
Take the coefficient of expansion to be 25 x 10^-6

• 0.258mm
• 0.1375mm
• 1.23mm
• 1.37mm

Calculate the change in temperature of an 900mm aluminium bar, that has increased in length to 901.035mm.
 α = 25 x 10^-6

• 12^oC
• 34.5^oC
• 57^oC
• 46^oC