Assuming an ideal gas, the speed of sound depends on temperature
only. Air is almost an ideal gas.
Assuming the temperature of 25°C in a "standard atmosphere", the
density of air is 1.1644 kg/m3, and the speed of sound is 346.13 m/s.
The velocity can't be specified, since the question gives no information
regarding the direction of the sound.
So we have a structured form, but can still move. If we had a cell wall we would be stiff objects since it’s just a cell membrane we can still have movement
There are two conditions necessary for total internal reflection, which is when light hits the boundary between two mediums and reflects back into its original medium:
Light is about to pass from a more optically dense medium (slower) to a less optically dense medium (faster).
The angle of incidence is greater than the defined critical angle for the two mediums, which is given by:
θ = sin⁻¹(
/
)
Where θ = critical angle, = refractive index of faster medium, = refractive index of slower medium.
Choice C gives one of the above necessary conditions.
Answer:
D) 15s
Explanation:
let Te be the period of the block-spring system on earth and Tm be the period of the same system on the moon.let g1 be the gravitational acceleration on earth and g2 be the gravitational acceleration on the moon.
the period of a pendulum is given by:
T = 2π√(L/g)
so on earth:
Te = 2π√(L/g1)
= 6s
on the moon;
Tm = 2π√(L/g2)
since g2 = 1/6 g1 then:
Tm = 2π√(L/(1/6×g1))
= √(6)×2π√(L/(g1))
and 2π√(L/(g1)) = Te = 6s
Tm = (√(6))×6 = 14.7s ≈ 15s
Therefore, the period of the block-spring system on the moon is 15s.
