Answer:
v_s = 34.269 m / s
Explanation:
This is a Doppler effect exercise, in this case the observer is fixed and the sound source is moving.
f ’= f
where the negative sign is used for when the source approaches the observer and the positive sign for when the source moves away from the observer
In this case when f ’= 5500 Hz approaches and when f’ = 4500 Hz moves away, let's write the two expressions together
5500 = f (
)
4500 = f (
)
let's solve these two equations
1.222 (v-v_s) = v + v_s
v_s (1+ 1.22) = v (1.222 -1)
v_s = v
the speed of sound in air is v = 343 m / s
v_s = 343 0.09990
v_s = 34.269 m / s
Answer:
T= 8.061N*m
Explanation:
The first thing to do is assume that the force is tangential to the square, so the torque is calculated as:
T = Fr
where F is the force, r the radius.
if we need the maximum torque we need the maximum radius, it means tha the radius is going to be the edge of the square.
Then, r is the distance between the edge and the center, so using the pythagorean theorem, r i equal to:
r = 
r = 0.5374m
Finally, replacing the value of r and F, we get that the maximun torque is:
T = 15N(0.5374m)
T= 8.061N*m
In physics we refer to how heavy the object is as the mass.
Fg = mass x acceleration due to gravity
Force is directly proportional to mass, thus if force of gravity increases mass also increases.
Answer:
16. 68.18 Km/h
17. 3 miles.
Explanation:
16. Determination of the speed
Distance travelled = 150 Km
Time = 2.2 hours
Speed =?
Speed is simply defined as the distance travelled with time. Mathematically, it is expressed as:
Speed = Distance / time
With the above formula, we can obtain the speed as follow:
Distance travelled = 150 Km
Time = 2.2 hours
Speed =?
Speed = Distance /time
Speed = 150 / 2.2
Speed = 68.18 Km/h
17. Determination of the distance.
Speed = 3 mph
Time = 1 hour
Distance =?
Speed = Distance /time
3 = distance / 1
Distance = 3 miles