Answer ) Sound level equation
The intensity of a sound wave is related to its amplitude squared by the following relationship: I=(Δp)22ρvw I = ( Δ p ) 2 2 ρ v w . Here Δp is the pressure variation or pressure amplitude (half the difference between the maximum and minimum pressure in the sound wave) in units of pascals (Pa) or N/m2.
The average angular acceleration of the fan is
The number of revolutions after time is given by
Acceleration is assumed to be constant, so and over the 2 second interval we have
so the answer is A.
D. About 25%
25% of stars have compainions
B.changing speed
Explanation:
because if it keeps changing directions and turning it's going to slow down and then speed up.
Speed = distance / time
S= 40 000m / 5400s
S= 7.41m/s