Answer:

Explanation:
As per Doppler's effect of sound the frequency of the sound when source is approaching the observer is given as

similarly when source is moving away from the observer then its frequency is given as

now we know that the ratio of two frequency is







Answer: Albert Einstein
Explanation:
Light can be considered as a wave or as particles, in this context Einstein proposed that light behaves like a stream of particles called <u>photons</u> with an energy, in order to correctly explain the photoelectric effect (in fact he won the 1921 Nobel Prize in Physics because of this explanation).
To uderstand it better:
The photoelectric effect is a fenomenom that consists in the emission of electrons that occurs when light falls on a metal surface under certain conditions.
This can only be explained based on the corpuscular model of light, that is, light is quantized.
So, Einstein theorized light as a stream of energy packets called photons, this energy is able to pull an electron out of the crystalline lattice of the metal and communicate, in addition, a kinetic energy.
I can say that the kinetic energy after the collision is less than it was before the collision. I can say this with confidence because you've said that some energy was used to deform the car, plus there was energy lost from the system in the form of heat.
Correct answer choice is :
B) Petroleum
Explanation:
Petroleum is commonly happening, yellow to the black liquid obtained in geological structures below the Earth's surface. It is usually filtered into different types of fuels. Petroleum outcomes involve transport fuels, fuel oils for heating and power generation, pavement and road oil, and feedstocks for making the compounds, plastics, and plastic elements that are in almost everything we use.
Answer:
R = 0.93 ohms
Explanation:
Let's start by calculating the resistance of the coil,
V = I ( R + r )
Make R the subject of the above equation.
Hence,
V = IR + Ir
V - Ir = IR
( V - Ir )/I = R
Given that V = 10V
r = 0.07ohms
I = 10A ( this is an assumption )
( 10 - 10×0.07 ) ÷ 10
R = 0.93 ohms
Note: r is the internal resistance, R is the resistance, I is the current and the emf is represented as V. Since current was supposed to be included in the question but it was not, hence it was assumed to be 10A . Meaning whatsoever value is given for current will be substituted into the equation. Thanks