Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
Answer:
Unbalanced force -
Explanation:
Unbalanced force is expected to cause a body to accelerate.
Answer:
1.435 x 10^-4 cm^3/s
Explanation:
coefficient of viscosity, η = 0.028 poise
Radius, R = 0.008 cm
length, l = 2 cm
Pressure, P = 5000 dyne/cm^2
The Poiseuille's formula is given below

Where, V is the rate of flow, that means volume flowing per second

V = 1.435 x 10^-4 cm^3/s
Thus, the rate of flow is 1.435 x 10^-4 cm^3/s.
Answer
D. The average speed is 2.5 meters/second, and the average velocity is 0 meters/second.
The difference between speed and velocity is that, speed is a scalar quantity while velocity is a vector quantity.
Average speed = total distance/Total time
= (150 + 150) / (2×60)
= 300/120
= 2.5 m/s
Average velocity = Total displacement/ Total time
= (150 + -150) / (2 × 60)
= 0/120
= 0 m/s
Answer: Solubility Rules
Explanation: I took it on Ap3x