Answer:
shift the wavelength of spectral lines
Explanation:
The Doppler effect is commonly used in the field of astronomy to study the motion of astronomical objects such as a star, planets, and distant galaxies. This results in the changing of wavelength and shifting of the spectral lines, due to the relative and continuous motion of the receiver and the source. This is known as the red-shifting, where the lights in the spectrum move towards the highest wavelength, i.e towards the red light. This Doppler effect signifies that the distance between the distant galaxies and earth increases with the increasing recessional velocity.
Answer:
The speed of the police car is 294 m/s
Explanation:
Given;
frequency of the siren in air, f = 280 Hz
speed of sound in air, v = 343 m/s
Determine the wavelength of the sound in air to the stationary car:
v = fλ
where;
λ is wavelength of the sound
λ = v/f
λ = 343 / 280
λ = 1.225 m
Now, determine the speed at which the police car is approaching the stationary car;
The actual frequency of the police car, F = 240 Hz
V = Fλ
Where;
V is speed of the police car
λ is the distance between the police car and the stationary car, (wavelength)
V = 240 x 1.225
V = 294 m/s
Therefore, the speed of the police car is 294 m/s
Answer:
= 308.5 N
Explanation:
acceleration of rocket for safe landing
= initial velocity
=final Velocity
m = mass of rocket
-5.625 
Upward force
F - mg = ma
F = ma+ mg
F = m(a+g)
m= mass
a = 5.625
g = 9.8
= 20(5.625 + 9.8)
= 308.5 N
Answer:
45 s .
Explanation:
The accelerator will first accelerate , then move with uniform velocity and at last it will decelerate to rest .
displacement s = ?
acceleration a = 1 m /s²
Final speed v = 5 m/s
initial speed u = 0
v² = u² + 2as
5² = 0 + 2 x 1 x s
s = 12.5 m
B) Let time of acceleration or deceleration be t
v = u + a t
5 = 0 + 1 t
t = 5 s
Similarly displacement during deceleration = 12.5 m
Total distance during uniform motion = 200 - ( 12.5 + 12.5 ) = 175 m .
velocity of uniform motion = 5 m /s
time during which there was uniform velocity = 175 / 5 = 35 s
Total time = 5 + 35 + 5 = 45 s .
The "ringing sound" are actually the soundwaves travelling from the phone to your ears.
