Please thoroughly explain these questions-STEP BY STEP-please 5. The siren on a
ID: 1267545 • Letter: P
Question
Please thoroughly explain these questions-STEP BY STEP-please
5. The siren on a police car emits waves with a frequency f=500 Hz. You are standing by the side of the road when a police car, sounding its siren, approaches you at 30.0 m/s. What frequency do you hear? The speed of sound is 340 m/s.
A)532 Hz B)540 Hz C)536 Hz D)544 Hz E)548 Hz
6.If the frequency of a harmonic oscillator doubles, by what factor does the maximum value of acceleration change?
A)2/pi B)4 C)2 D) Squareroot(2)
7.The moment of inertia of a solid cylinder about its axis is given by 0.5 MR^2. If this cylinder rolls without slipping, the ratio of its rotational kinetic energy to its transitional kinetic energy is
A) 1:2 B)2:1 C)1:3 D)1:1
8. In Figure 10.4 a given force F is applied to a rod in several different ways. In which case is the torque due to F about the pivot P greatest?
A) 3 B)4 C)2 D)5 E)1
Explanation / Answer
5)using doppler's equation,
f=fo*(vc-vd)/(vc-vs)
=500*(340)/(340-30)
=548.387 Hz
E)548 Hz
6) a=w^2*r
so it double by a factor of 4
7)ratio= (0.5mv^2/(0.5Iw^2))^-1
=2:1
8)torque= r X F
=rF sin(x)
since sin(x) is maximum at 90 degrees,
the correct answer is figure 1 (option E)