9 thats you electron number and what makes up 9 is 3
Answer: The frequency heard will be f = 275.675Hz
Explanation: When an object emitting sound is moving, it occurs a phenomenon called Doppler shift or Doppler effect. What happens is that the sound gets higher when the moving object comes closer the observer and becomes lower after it passes, This change is due to the quantity of waves that passes through an area in an unit of time.
The formula to calculate the Doppler effect is as follows
f = (
) · f₀
f is the observed frequency;
c is the speed of sound;
Vs is velocity of the source;
f₀ is the emitted frequency of source;
Substituting and calculating,
f =
· 300
f = 275.675 Hz
Thus, the frequency heard by the police officer is 275.675Hz.
Answer:
Paul B. MacCready, 81; inventor of human-powered aircraft, other innovations. Paul B. MacCready, the Caltech-trained scientist and inventor who created the Gossamer Condor -- the first successful human-powered airplane -- as well as other innovative aircraft, has died. He was 81.
Explanation:
Answer:
Low satellite has high orbital velocity
Explanation:
let v be the orbital speed of the satellite orbiting at a height h is given by

where, M be the mass of planet, r be the radius of planet and h be the height of planet from the surface of planet.
here we observe that more be the height lesser be the orbital velocity.
So, a satellite which is at low height has high orbital velocity.
Answer:
Explained
Explanation:
Lunar mountains are smoothly rounded rather than having sharp, pointed peaks because the lunar moons are formed because of the impact of asteroids and comets on its surface whereas the Earth mountains are formed because of the surface activity of volcanos, collision of land masses and activity of plate tectonics that is why they have sharp and pointed tops.