Answer: observed frequency (f') = 511.97Hz
Explanation: when there is a relative motion between an observer and a sound source, the frequency of sound wave perceived by the observer is different from the frequency of originally sent out by the sound source.
This is called Doppler effect and given mathematically below as
f' = (v + v') /(v- vs) * f
f' = observed frequency
v = speed of sound in air = 340m/s
v' = velocity of observer= 45m/s
vs = velocity of source relative to observer = - 36m/s ( the negative sign came as a result of the fact that the velocity of the source is in opposite direction to the velocity of the observer)
f = original frequency of sound source = 500Hz
f' = (340 + 45)/{340 -(-36)} * 500
f' = 385/ (340 + 36) * 500
f' = 385/ 376 * 500
f' = 1.0239 * 500
f' = 511.97Hz
<span>Answer:
So it gets to the top of the ramp and stops. The parallel force pushing it down the ramp is mg sin θ, but for it to move, the frictional force must be overcome. This frictional force is μmg cos θ, where μ is the coefficient of static friction. For movement, then,
mg sin θ > μmg cos θ ==> tan θ > μ ==> θ > arctan 0.5 = 26.565° ==> θ = 27°</span>
Explanation:
Given that,
Mass of the object, m = 7.11 kg
Spring constant of the spring, k = 61.6 N/m
Speed of the observer, 
We need to find the time period of oscillation observed by the observed. The time period of oscillation is given by :
Time period of oscillation measured by the observer is :
So, the time period of oscillation measured by the observer is 5.79 seconds.
Answer:
≈933.3kg/m^3
Explanation:
Density=Mass/Volume
11200kg/12.0= 933.3333kg/m^3
