Answer:
a) ΔФ = 5.54 rad
, b) f = 140 Hz
Explanation:
a) This is a sound interference exercise, which is described by
Δr /λ = ΔФ / 2π
ΔФ = Δr 2π /λ
Let's find the path difference
Δr = r₂ -r₁
r₁ = 4m
r₂ = √ (x² + y²) = √(3² + 4²) = 5 m
Δr = 1 m
To find the wavelength we use the relation of the speed of sound
v = λ f
λ = v / f
λ = 340/300
λ = 1,133 m
We substitute
ΔФ = 2π 1 /1.133
ΔФ = 5.54 rad
b) to have a minimum intensity the phase difference must be π radians
λ = Δr 2π /Ф
λ = 1 2π /π
λ = 2m
We look for the frequency
v = λ f
f = v /λ
f = 340/2
f = 140 Hz
RDA stands for Recommended Daily Allowance. To determine the amount needed of a certain adult per day, we simply multiply the mass of the adult to the value of RDA. For this case, we do as follows:
Daily requirement = 12 mg/kg ( 78 kg ) = 936 mg of lysine = 936000 g
Answer:
It takes 6.52 s to complete the 150 m track.
Explanation:
Let's find the position of the cyclist during the acceleration.
Now, the final speed at this distance will be:
Now, we know that x(tot) = 150 m, the remaining part will be:
Therefore, the time is:
I hope it helps you!
D would be correct.
Have a merry Christmas!
Answer:
False
Explanation:
Acceleration is the rate of change of velocity
Acceleration the negative acceleration means the speed of the object decreases
Negative acceleration does not mean that velocity will also negative
For example if the the speed of the object decreases from 20 m/sec to 15 m/sec in 5 sec then acceleration will be here acceleration is negative but velocity is positive