The speed of sound is greater in ice (4000 m/s), then in water (1500 m/s), then in air (340 m/s). The explanation for this is the differente state of the matter in the three cases.
In fact, sound waves travel faster in solids (like ice), then in liquids (like water), then in gases (like air). This is because the speed of the sound wave depends on the density of the medium: the greater the density, the faster the sound wave. This can be easily understood by thinking at how a sound wave propagates: a sound wave is a vibration of molecules, which is transmitted throughout the medium by collision of the molecules. Therefore, the smaller the spacing between the molecules (such as in solids), the more efficient is the propagation, and so the sound wave is faster. On the contrary, there is a large spacing between molecules in gases (such as in the air), so there are less collisions between the molecules and so the wave is not transmitted efficiently, and so it has less velocity.
Answer:
b
Explanation:
because all are factors that determine the resistivity of a material
Explanation:
physical exertion.
lack of physical activity.
lack of sleep.
being overweight or obese.
periods of emotional stress.
boredom.
grief.
taking certain medications, such as antidepressants or sedatives.
Answer:
Solid-state
Explanation:
A solid-state device can be defined as a crystalline material that is typically made up of semiconductor and as such controls the number and rate of flow of charged carriers such as holes or electrons.
Some examples of a solid-state device are light emitting diodes (LED), integrated circuit (IC), Transistors, liquid crystal display (LCD) etc.
A solid-state device such as a transistor, refers to a semiconductor component that is used to control the flow of voltage or current and as a gate (switch) for electronic signals. Thus, a transistor allows for the amplification, control and generation of electronic signals in a circuit.
Hence, solid-state devices need constant power to operate. The timing functions are initiated by the presence or absence of a separate "trigger" signal.
Basically, these solid-state devices use the optical and electrical properties of semiconductor components such as transistors, triacs, thyristors, diodes to perform its input-output switching and isolation functions.
The object is fixed relative to the motion you are trying to describe.
