Answer:
time taken by the wave to reach the person is 0.2 s
Explanation:
As we know that the speed of the wave is given as

here we know that the wavelength of the wave is


now speed of the wave is given as


Now time taken by the wave to reach 5 m distance is



This question involves the concepts of echo, ultrasonic images, ultrasonic sound waves.
The process of ultrasonic images uses the "echo" property of the sound waves.
Echo is the property of the sound wave by the virtue of which the sound wave reflects back to the source of the sound after hitting a surface or an object.
Ultrasonic images are obtained from inside organs of our body. This process involves the use of ultrasonic sound waves that have a frequency greater than 20,000 Hz. These sound waves are out of the range of audible sound by the human ear. When these ultrasonic sound waves are sent in form of pulses into the human body by the use of probes, they reflect back from the tissues of different organs to the probe. The probe then records the reflection properties of these sound waves and displays them in form of an image, known as ultrasonic images.
Learn more about echo here:
brainly.com/question/14335186?referrer=searchResults
The attached picture shows the process of ultrasonic imaging.
Answer: Light could be thought of as a stream of tiny particles discharged by luminous objects that travel in straight paths.
Explanation:
We can define "radiation" as the transmision of energy trough waves or particles.
Particularly, light is a form of electromagnetic radiation, so the "tiny particles" of light are discharged by a radiating object, particularly we can be more explicit and call it a luminous object, in this way we are being specific about the nature of the radiation of the object.
Answer:
2m/s²
Explanation:
velocity = displacement (distance in a specified direction /time
Answer:
The change in kinetic energy (KE) of the car is more in the second case.
Explanation:
Let the mass of the car = m
initial velocity of the first case, u = 22 km/h = 6.11 m/s
final velocity of the first case, v = 32 km/h = 8.89 m/s
change in kinetic energy (K.E) = ¹/₂m(v² - u²)
ΔK.E = ¹/₂m(8.89² - 6.11²)
= 20.85m J
initial velocity of the second case, u = 32 km/h = 8.89 m/s
final velocity of the second case, v = 42 km/h = 11.67 m/s
change in kinetic energy (K.E) = ¹/₂m(v² - u²)
ΔK.E = ¹/₂m(11.67² - 8.89²)
= 28.58m J
The change in kinetic energy (KE) of the car is more in the second case.