A control is something you don't touch/change in a exprement, a constant is the same as the control, the independent is the one the you do vhange, the dependet is the one that you observe/ use your 5 sences with.
Answer:
22.5J
Explanation:
Here the force is given. Also, the displacement is given as 30cm.
First we should check if all the values are in their standard form.
Here 30cm should be converted to metre by dividing it with 100.
Which would give us 0.3m
Now we use the equation W=force x displacement =75 x 0.3=22.5J
I hope this satisfies you. If u have any further questions please let me know.
I hope u will follow me and make this the brainliest answer.
I'm assuming it was to keep the data consistent? The further you are from a heat source the less heat will get to you as the temperature tries to reach equilibrium and the waves start to spread out, so you should keep everything the same distance to get consistent results. I don't have any information so this is just my assumption