Yes A diamond* is a pure substance
Answer:
a) diffraction
Explanation:
Diffraction occurs when waves pass through small openings, around obstacles or sharp edges.When an opaque object is between the point of light and a screen, the border between the shaded and illuminated regions on the screen is not defined. A careful inspection of the scrubber shows that a small amount of light is diverted to the shaded region. The region outside the shadow contains bright and dark altered bands, where the intensity of the first band is brighter than the region of uniform illumination.
Answer:
Explanation:
Wave length of sound from each of the speakers = 340 / 1700 = .2 m = 20 cm
Distance between first speaker and the given point = 4 m.
Distance between second speaker and the given sound
= √ 4² + 2² = √16 +4 = √20 = 4.472 m
Path difference = 4.472 - 4 = .4722 m.
Path difference / wave length = 0.4772 / 0.2 = 2.386
This is a fractional integer which is neither an odd nor an even multiple of half wavelength. Hence this point of neither a perfect constructive nor a perfect destructive interference.
Answer:

Explanation:
According to the newton's second law of motion we can apply F=ma hear
Force = mass * acceleration
(assume the piano is moving left side )
←F = ma

Answer: Weight = 98.1N
Explanation:
Density of water = 1000 kg/m^3
Given that the Plastic foam is about 0.10 times as dense as water. That is,
Density of plastic foam = 0.1 × 1000 = 100kg/m^3
The volume V = 1 ×1×0.1 = 0.1 m^3
Density is the ratio of mass to volume
Density = mass/volume
Let us substitute for density and volume to get mass.
100 = M/0.1
Make M the subject of formula
M = 100 × 0.1 = 10 kg
Weight = mg
Where g = 9.81 m/s
Substitute the M and g into the formula
Weight = 10 × 9.81 = 98.1 N
Therefore, the weight of the brick is 98.1 N