Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate . this means that electromagnetic waves can travel not only through air and solid materials bit also through vacuum of space.
Answer:
C. Equals the sum of all forms of energy contained within the system.
D. Equals the heat entering the system at constant volume.
E. Equals the heat entering the system plus the work done on the system
Explanation:
Internal energy is defined as the sum of internal kinetic energy and internal potential energy, that is, the energy contained within the system.
The first law of thermodynamics relates the change in the internal energy with the heat entering the system (Q) and work done on the system (W), with the following expression:

If the system is at constant volume the work done is zero. Therefore, the heat entering the system increases its internal energy:

A. cgi... they're usually filmed with a greenscreen and is keyed out in editing. known as chroma keying
Answer:
the pe at the top of the building: 784 J
the pe halfway through the fall: 392 J
the pe just before hitting the ground: 784 J
Explanation:
Pls brainliest me
I had this question before
Answer:
D.vibrations that cause changes in air pressure
Explanation:
Sound is a type of wave.
A wave is a periodic disturbance/oscillation that trasmits energy without transmitting matter. There are two different types of waves:
- Transverse waves: in a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. These waves are characterized by the presence of crests (points of maximum positive displacement) and troughs (points of maximum negative displacement). Examples of transverse wave are electromagnetic waves.
- Longitudinal waves: in a longitudinal wave, the direction of the oscillation is parallel to the direction of motion of the wave. These waves are characterized by the presence of compressions (regions where the density of particle is higher) and rarefactions (regions where the density of particle is lower). Examples of longitudinal waves are sound waves.
Sound waves, in particular, consist of vibrations of the particles in a medium - most commonly, air - that occur back and forth along the direction of motion of the wave. Because of these motion, the air will have areas of higher pressure (which correspond to the compressions), where the density of particles is higher, and areas of lower pressure (which correspond to the rarefactions), where density of particles is lower.