Answer : The average speed of the object is, 10 m/s
Solution : Given,
Distance traveled by the object = 60 m
Time taken = 6 s
Average speed : It is defined as the distance traveled by an object in per unit time. The unit of average speed is, meter/second.
Formula used :

Now put all the given values in this formula, we get the average speed of an object.

Therefore, the average speed of the object is, 10 m/s
These could all go either way, hardness and other special properties are what I'm guessing would be the most accurate in determining the kind of material.
luster, cleavage, streak, and color can all be affected by other factors. but I guess cleavage would also be accurate. so I guess hardness special properties and cleavage would be the most reliable.
Answer:
Superman - six flags in San Antonio
Explanation:
Ba(OH)₂(aq) + 2HNO₃(aq) = Ba(NO₃)₂(aq) + 2H₂O(l)
At the reaction of barium hydroxide with nitric acid there are no visual changes.
Ba(OH)₂(aq) + H₂SO₄(aq) = BaSO₄(s) + 2H₂O
At the reaction of barium hydroxide with sulfuric acid the precipitat of white color is formed.