There are different options here but all of them work by approximating and assuming.
i) that the boulder is above ground.
ii) that the bottom surface of the boulder is known.
iii) the shape of the boulder is taken into account.
The most accurate way is measuring it by displacement method but the boulder is immovable hence the volume can be calculated by measuring the boulder or a waterproof box to be built around the boulder and calculate the volume occupied by boulder.
All the above methods are estimating methods.
*Another way to find the density is through specific gravity.
S.G = <u>Density</u><u> </u><u>of</u><u> </u><u>object</u>
Density of water
If the material that makes the boulder is known that is if it's stone or a mineral then the specific gravity can be found.
If the boulder is purely rock then S.G lies between 3 - 3.5 and the density of water is known thus the density of the boulder can be found without moving the boulder.
This is what I think after correction and allthe best!
Answer:
2.11eV
Explanation:
We know that speed of light is it's wavelength times frequency.
Planck's constant is 
The energy gap is calculated by multyplying the light's frequency by planck's constant:
Hence, the energy gap is 2.11eV
Answer:
a) and c).
Explanation:
For a complete destructive interference occur, it must be met the following condition relating the wavelength, and the difference in the paths taken by the sound emitted by the sources until arriving to the listening point:
d = |dA- dB| = (2n-1)*(λ/2)
For n= 1, d = λ/2 = 0.25 m, it doesn't meet any of the cases.
For n=2, d= 3*(λ/2) = 0.75 m
In the case a) we have dA = 2.15 m and dB = 3.00 m, so dB-dA = 0.75 m, which means that in the location stated by case a) a complete destructive interference would occur.
For n=3, d= 5*(λ/2) = 5*0.25 m = 1.25 m.
This is just the case c) because we have dA = 3.75 m and dB = 2.50 m, so dA-dB = 1.25 m, which means that in the location stated by case c) a complete destructive interference would occur also.
The remaining cases don't meet the condition stated above, so the statements found to be true are a) and c),
Answer:
33.5 kJ
Explanation:
here there is no difference is made in the temperature. Only thing happens here is the conversion of the ice in to water of 0 degree. The heat energy taken from the outside is spent for this conversion.
we have ice 100g =0.1 kg
Appplying Q=mL
Q= 
Q = 33 500 J
Q = 33.5 kJ
