Without being provided a list of items, I would have to generally say that everything around you is matter. There are a few exceptions to this list, but a general rule of thumb is anything you can touch, taste, smell or hold would be considered matter. Sound, light, time (Dr. Who may disagree) and heat would be considered non-matter items.
Answer:
Explanation:
Suppose when bucket is half full it has a mass of 2 m rotating in a circle of radius r
When Bucket is quarter full then it has a mass of m rotating in a circle of radius r.
When an object moves in a circular path then it experiences an inward force which is given by

where v=velocity of bucket
Force in case 2 is given by

Thus
therefore force required in half bucket is more than force required in quarter bucket full.
Answer:
a = 2.275 10⁻⁴ m
Explanation:
This is a diffraction problem that is described by the equation
a sin θ = m λ
The first dark minimum occurs for m = 1
a = λ / sin θ
The angle can be found by trigonometry,
tan θ = y / x
θ = tan⁻¹ y / x
Let's reduce the magnitudes to the SI system
y = 8.24 mm = 8.24 10⁻³ m
λ = 625 nm = 625 10⁻⁹ m
θ = tan⁻¹ 8.24 10⁻³ / 3.00
θ = 0.002747 rad
We calculate
a = 625 10⁻⁹ / sin 0.002747
a = 2.275 10⁻⁴ m
Answer;
26.45cm
See attached file for explanation