Answer:
The Internal energy of the gas did not change
Explanation:
In this situation the Internal energy of the gas did not change and this is because according the the first law of thermodynamics
Δ U = Q - W ------ ( 1 )
Δ U = change in internal energy
Q = heat added
W = work done
since Q = W. the value of ΔU will be = zero i.e. No change
Answer:
you would have to stand 6 ft back
Explanation:
Angry sound level = 70 db
Soothing sound level = 50 db
Frequency, f = 500 Hz
Assuming speed of sound = 345 m/s
Density (assumed) = 1.21 kg/m^3
Reference sound intensity, Io = 1*10^-12 w/m^2
Part (a): Initial sound intensity (angry sound)
10log (I/Io) = Sound level
Therefore,
For Ia = 70 db
Ia/(1*10^-12) = 10^(70/10)
Ia = 10^(70/10)*10^-12 = 1*10^-5 W/m^2
Part (b): Final sound intensity (soothing sound)
Is = 50 db
Therefore,
Is = 10^(50/10)*10^-12 = 18*10^-7 W/m^2
Part (c): Initial sound wave amplitude
Now,
I (W/m^2) = 0.5*A^2*density*velocity*4*π^2*frequency^2
Making A the subject;
A = Sqrt [I/(0.5*density*velocity*4π^2*frequency^2)]
Substituting;
A_initial = Sqrt [(1*10^-5)/(0.5*1.21*345*4π^2*500^2)] = 6.97*10^-8 m = 69.7 nm
Part (d): Final sound wave amplitude
A_final = Sqrt [(1*10^-7)/(0.5*1.21*345*4π^2*500^2)] = 6.97*10^-9 m = 6.97 nm
Given Information:
slope angle = θ = 30°
spring constant = k = 30 N/m
compressed length = x = 10 cm = 0.10 m
mass of ice cube = m = 63 g = 0.063 kg
Required Information:
distance traveled by ice cube = d = ?
Answer:
distance traveled by ice cube = 0.48 m
Explanation:
Using the the principle of conversation of energy, the following relation holds true for this case,
mgh = 1/2*kx²
h = 1/2*kx²/mg
Where h is the height of the slope, m is the mass of ice cube, k is the spring constant and x is the compressed length o the spring and g is gravitational acceleration.
h = 1/2*kx²/mg
h = 1/2*30(0.1)²/0.063*9.8
h = 0.242 m
From trigonometry ratio,
sinθ = h/d
d = h/sinθ
d = 0.242/sin(30)
d = 0.48 m
Therefore, when the ice cube is released, it will travel a total distance 0.48 up the slope before reversing direction.