Answer:
G.) The number atoms of that element in the molecule
Explanation:
F is incorrect because the coefficient represents the amount of one type of molecule, not the subscript
G is correct because subscripts represent how many atoms of that element are present in that single molecule
H is incorrect because energy is not represented in this simple type of equation
J is incorrect because it doesn't even make sense
Answer:
about 14.7°
Explanation:
The formula for the angle of the first minimum is ...
sin(θ) = λ/a
where θ is the angle relative to the door centerline, λ is the wavelength of the sound, and "a" is the width of the door.
The wavelength of the sound is the speed of sound divided by the frequency:
λ = (340 m/s)/(1300 Hz) ≈ 0.261538 m
Then the angle of interest is ...
θ = arcsin(0.261538/1.03) ≈ 14.7°
At an angle of about 14.7°, someone outside the room will hear no sound.
Answer:
KE = 0.162 KJ
Explanation:
given,
mass of bullet (m)= 20 g = 0.02 Kg
speed of the bullet (u)= 1000 m/s
mass of block(M) = 1 Kg
velocity of bullet after collision (v)= 100 m/s
kinetic energy = ?
using conservation of momentum
m u = m v + M V
0.02 x 1000 = 0.02 x 100 + 1 x V
20 = 2 + V
V = 18 m/s
now,
Kinetic energy of the block
KE = 162 J
KE = 0.162 KJ
Answer:
The weight of the body, W = 793.8 m/s²
Explanation:
Given,
The volume of the body, v = 45,000 cm³
The density of the body, ρ = 1.8 g/cm³
The mass of the body is given by the formula,
m = ρ x v
= 1.8 g/cm³ x 45,000 cm³
= 81,000 g
Hence, the mass of the body is m = 81 kg
The weight of the body,
W = m x g
= 81 kg x 9.8 m/s²
= 793.8 m/s²
Hence, the weight of the body, W = 793.8 m/s²
