when a car is heated , say by taking it to a desert, it expands. Is the increase in length of the car greater than, less than, or equal to its increase in height?

  ΔL = Δh

since the length of the carriages is greater than their height, the length expansion is greater than the height expansion

Explanation:

This is an exercise in thermal expansion, which is described by the expression for one dimension

          ΔL = α L₀ ΔT

For the analysis of this exercise we will assume that the sides are independent

Let's look for the condition of the length of the car

         ΔL / L₀ = α ΔT

The height delay (h) is

         Δh / h₀ = α  ΔT

we can match the two expressions

       ΔL / L₀ = Δh / h₀

        ΔL = Δh

since the length of the carriages is greater than their height, the length expansion is greater than the height expansion

battery with hi vtge high val resist in series

b.a device that inputs heat into a cool object