Answer:
(d) a net external force must be acting on the system
Explanation:
Momentum is given as the product of mass and velocity.
P = MV
According to Newton's second law of motion, " Force applied to a body (system) is directly proportional to the rate of change of momentum of the body (system) which takes place in the direction of the applied force (external force).
F ∝ΔMV
Therefore, If the total momentum of a system is changing, a net external force must be acting on the system.
(d) a net external force must be acting on the system
Answer:
newton's first law
Explanation:
this is because newton's first law of motion states that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.
hope this helps, if you want more elaboration, tell me
<u>Answer</u>
longitudinal wave because the particles move parallel to the direction that the wave is traveling.
<u>Explanation</u>
There are 2 types of a wave, electromagnetic and mechanical wave. These waves can also be categorized into two, longitudinal ans transverse waves.
longitudinal wave is a wave whose particles vibration is in the direction of wave travel.
Transverse wave is a wave whose vibration of particles is perpendicular to the direction of wave travel.
First of all, I is proportional V according to the Ohm's Law. R is merely a constant you need to obtain an equation. However, it is true that R changes with temperature and pressure, therefore Ohm's Law is only applicable in an invariable environment. Also this constant R is different for different materials.
So, do not get confused.
Ohm's law is not a universal law, please remember that as well. Some materials do not follow it and we call them non-ohmic conductors. I hope I helped! ^-^
Answer:Broadly speaking, all energy in the universe can be categorized as either potential energy or kinetic energy. Potential energy is the energy associated with position, like a ball held up in the air. When you let go of that ball and let it fall, the potential energy converts into kinetic energy, or the energy associated with motion.
EXAMPLES: There are five types of kinetic energy: radiant, thermal, sound, electrical and mechanical. Let's explore several kinetic energy examples to better illustrate these various forms.
