How does wind from? nnnnnnnnnn

A woman is sitting at a bus stop when an ambulance with a siren wailing at 317 Hz approaches at 69 miles per hour (mph). Assume

xxMikexx [17]

Answer:

a) 30.84m/s

b) 348.32Hz

c) 32.34m/s

d) 289.69Hz

Explanation:

a) If 1 mile=1609,34m, and 1 hour=3600 seconds, then 69mph=69*1609.34m/3600s=30.84m/s

b) Based on Doppler effect:

/*I will take as positive direction the vector $\vec r_{observer}-\vec r_{emiter}$ */

$f_{observed}=(\frac{v_{sound}-v_{observed}}{v_{sound}-v_{emited}})f_{emited}$

$f_{observed}=(\frac{343m/s-0m/s}{343m/s-30.84m/s})317Hz=348.32Hz$

c) $350Hz=(\frac{343m/s-0m/s}{343m/s-v_{ambulance}})317Hz, V_{ambulance}=343m/s-\frac{317Hz}{350Hz}.343m/s=32.34m/s$

d) $f_{observed}=(\frac{343m/s-0m/s}{343m/s+32.34m/s})317Hz=289.69Hz$

3 0

3 years ago

1.An 8-kilogram bowling ball is rolling in a straight line toward you. If its momentum is 16 kg•m/s, how fast is it traveling?

Lilit [14]

1. An 8-kilogram bowling ball is rolling in a straight line toward you. If its momentum is 16 kg•m/s, how fast is it traveling?

momentum = mass x velocity
16 = 8 x velocity
velocity = 2 m/s

2.A beach ball is rolling in a straight line toward you at a speed of 0.5 m/sec. Its momentum is 0.25 kg•m/s. What is the mass of the beach ball?

momentum = mass x velocity
0.25 = m x 0.5
mass = 0.5 kg

3.A 4,000-kilogram truck travels in a straight line at 10.0 m/s. What is its momentum?
Momentum = (mass) x (speed) = (4,000) x (10) = 40,000 kilogram-meters/second

4.A 1,400-kilogram car is also traveling in a straight line. Its momentum is equal to that of the truck in the previous question. What is the velocity of the car?

40,000 kilogram-meters/second = 1400 x velocity
velocity = 28.6 m/s

5.Which would take more force to stop in 10 seconds: an 8.0-kilogram ball rolling in a straight line at a speed of 0.2 m/s or a 4.0-kilogram ball rolling along the same path at a speed of 1.0 m/s?

F1 = 8 x 0.2 / 10 = 0.16 N
F2 = 4 x 1.0 / 10 = 0.4 N ----> take more force

6.The momentum of a car traveling in a straight line at 20 m/s is 24,500 kg•m/s. What is the car’s mass?

24500 = mass x 20
mass = 1225 kg

7.Another pitcher throws the same baseball in a straight line. Its momentum is 2.1 kg•m/s. What is the velocity of the ball?

2.1 = 0.5 x velocity
velocity = 4.2 m/s

8 A 1-kilogram turtle crawls in a straight line at a speed of 0.01 m/s. What is the turtle’s momentum?

momentum = 1 x 0.01 = 0.01 kg m/s

4 0

3 years ago

fuel was consumed at a certain rate of 0.05Kg\s in a rocket engine and ejected as a gas with a speed of4000m\s . Determine the t

ivann1987 [24]

Answer:

Thrust = 200 N

Explanation:

The engine thrust can be found by using the following formula:

$Thrust = mv$