26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
Relative density is defined as:
dr = ds / dw
where:
dr: relative density
ds: density of the substance.
dw: density of water.
In this case we have the relative density of oak wood:
dr = 0.64.
We want to find the density of the substance: ds
Therefore we need to know the density of water in the cgs unit system:
dw = 1g / c ^ 3
Finally:
ds = dr * dw
ds = 0.64 * 1 g / cm ^ 3
ds = 0.64 g / c ^ 3
The density of the oak wood in cgs is 0.64 g / cm ^ 3
Answer:
Wavelength = 3.74 m
Explanation:
In order to find wavelength in "metres", we must first convert megahertz to hertz.
1 MHz = 1 × 10⁶ Hz
80.3 Mhz = <em>x</em>
<em>x </em>= 80.3 × 1 × 10⁶ = 8.03 × 10⁷ Hz
The formula between wave speed, frequency and wavelength is:
v = fλ [where v is wave speed, f is frequency and λ is wavelength]
Reorganise the equation and make λ the subject.
λ = v ÷ f
λ = (3 × 10⁸) ÷ (8.03 × 10⁷)
λ = 3.74 m [rounded to 3 significant figures]
recoils and must be tethered or he's gone.
No, you can't aim where you see the fish, because refraction will change the position of the fish and make it appear in a different position from where it actually is.
Hope this helps!
