Pure substance has a definite and constant composition-like salt or sugar. A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary.
Mixtures are physical combinations of pure substances that have no definite or constant composition — the composition of a mixture varies according to who prepares the mixture.
It's the Doppler Effect that "up and down sound."
I was on Yahoo--- Brainly doesn't have an option for Credientials or Site credit, so I'll just put this in the quotes:
<span>The formula for doppler effect is always (s is speed and f is frequency): </span>
<span>f_perceived.by.observer = f_of.emitted.wave * (s_wave + s_observer) / (s_wave + s_source.of.wave) </span>
<span>And you should pay attention to the signs: </span>
<span>s_observer is positive if the receiver is moving towards the source, negative otherwise </span>
<span>s_source.of.wave is positive if the source is moving away from the observer, negative otherwise </span>
<span>Applying it to this case: </span>
<span>s_source.of.wave = ? (positive), speed of ambulance </span>
<span>s_observer = + 2.44 m/s speed cyclist </span>
<span>f_of.emitted.wave =1800 Hz frequency of whine </span>
<span>f_perceived.by.observer = 1760 frequency heard by cyclist </span>
<span>s_wave = 343 m/s speed of sound in air </span>
<span>Now you know every value in the equation for doppler effect except by s_source.of.wave, so you can solve for s_source.of.wave.</span>
It won't happen anything i think it will just be a something like a small thing
Answer:
1.51783893986
Explanation:
One kilogram is equal to 9.81 Newtons
You have 14.89N, divide this by 9.81 and u get the mass in KG
so u do 14.89/9.81 = 1.51783893986 or 1.52kg (2dp)
P=4800kgm/s
As
p=mΔv
where p is momentum, m is mass and v is velocity
Given values is
m =1200kg
Δv= 17m/s-13m/s=4m/s
Now
p=mΔv
p=(1200kg)*(4m/s)
p=4800kgm/s