Answer:
the signs of heat and work are; -Q and -W
Explanation:
The first law of thermodynamics is given by; ΔU = Q − W
where;
ΔU is the change in internal energy of a system,
Q is the net heat transfer (the sum of all heat transfer into and out of the system)
W is the net work done (the sum of all work done on or by the system).
Now, The system in this case is the tire and since the air gets warmer, heat must have left the system. Therefore Q is negative (-Q).
Since work is done by the system, W remains negative.
Thus, the signs of heat and work are; -Q and - W
Answer:
Applying enough force in one direction to move the object, making kinetic energy.
Explanation:
Simpleness
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.
They are 50 stars in the U.S flag.
Wood isn’t a medium. Pls give brainliest