Question

the dog in the gif above is wearing boots! while this may look silly and cute, boots like this can protect dogs feet from cuts and burns.
a big concern for dog owners is making sure their pets are safe as the temperature of the pavement begins to rise. on a hot, sunny day the temperature of the sidewalk can get as high as 125°f (52°c). this can cause pain and burns to a dogs paws. table 1 below shows the relationship between air temperature and the temperature reached by different surfaces.
a student wants to perform an investigation to test how the material of the dog boots affects how much it heats up from a hot surface. four investigation procedures are shown in the chart.
the student should perform procedure number
because the boot and surface should be at to energy flow and the investigation should be performed in system.
drag the answers below into the grey placeholders above

Explanation:

Step1: Identify the control variables

In an experiment to test how the material of the dog boots affects heating from a hot surface, the surface temperature should be the same (control variable). Procedure 2 has the boot and surface at the same temperature ($52^{\circ}C$).

Step2: Analyze energy flow

We want to allow energy flow (heat transfer) from the surface to the boot. If the surface and boot are at the same temperature initially, we can observe the heating effect due to the material.

Step3: Consider the system type

It should be a closed system to isolate the variables related to the boot - surface interaction.

Answer:

Procedure number 2 because the boot and surface should be at the same temperature to allow energy flow and the investigation should be performed in a closed system.