Answer:
We know that the speed of sound is 343 m/s in air
we are also given the distance of the boat from the shore
From the provided data, we can easily find the time taken by the sound to reach the shore using the second equation of motion
s = ut + 1/2 at²
since the acceleration of sound is 0:
s = ut + 1/2 (0)t²
s = ut <em>(here, u is the speed of sound , s is the distance travelled and t is the time taken)</em>
Replacing the variables in the equation with the values we know
1200 = 343 * t
t = 1200 / 343
t = 3.5 seconds (approx)
Therefore, the sound of the gun will be heard at the shore, 3.5 seconds after being fired
If speed = distance/time , then time = speed/distance.
So...
Speed of light = 3*10^8(m/s)
Average distance from Earth to Sun = 149.6*10^9(m)
Therefore, t=(3*10^8(m/s))/(149.6*10^9(m))
I hope this was a helpful explanation, please reply if you have further questions about the problem.
Good luck!
Answer:
axial stress in the diagonal bar =36,000 psi
Explanation:
Assuming we have to find axial stress
Given:
width of steel bar: 1.25 in.
height of the steel bar: 3 in
Length of the diagonal member = 20ft
modulus of elasticity E= 30,000,000 psi
strain in the diagonal member ε = 0.001200 in/in
Therefore, axial stress in the diagonal bar σ = E×ε
= 30,000,000 psi× 0.001200 in/in =36,000 psi
Answer:
2046.37 kPa
Explanation:
Given:
Number of moles, n = 125
Temperature, T = 20° C = 20 + 273 = 293 K
Radius of the cylinder, r = 17 cm = 0.17 m
Height of the cylinder, h = 1.64 m
thus,
volume of the cylinder, V = πr²h
= π × 0.17² × 1.64
= 0.148 m³
Now,
From the ideal gas law
we have
PV = nRT
here,
P is the pressure
R is the ideal gas constant = 8.314 J / mol. K
thus,
P × 0.148 = 125 × 8.314 × 293
or
P × 0.148 = 304500.25
or
P = 2046372.64 Pa = 2046.37 kPa
Answer:
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7 m/s
Explanation:
The Doppler shift equation is given as follows;
Where:
f' = Required observed frequency = 20.0 kHz
f = Real frequency = 21.0 kHz
v = Sound wave velocity = 330 m/s
= Observer velocity = X m/s
= Source velocity = 0 m/s (Assuming the source is stationary)
Which gives;
330 - = (20/21)*330
= 330 - (20/21)*330 = 15.7 m/s
The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7 m/s.
