According to my guesses, he should have swung the pendulam bob and noted its time period. In order to observe the effect of mass, he would have repeated the experiment with varied pendulam bobs. Hope this helped!
Explanation:
this is due to the roughness of the metal like you mentioned aluminum and iron are rough and don't provide a reflective surface as good as a mirror
Get the amount of money in a day, (8)(7)=$56 per day
5 days per week, 56(5)=280
To conclude, she gets $280 in a week.
