Answer:
His first law states that unless it is forced to change its state through external force, every object will remain stationary or move in a straight line at a constant speed. It is usually taken as the definition of inertia.
Explanation:
Answer:
The frequency increases, and the pitch increases
Explanation:
- Doppler's law of sound is applicable in such case when the observer or the sound source or both are moving relative to each other.
- In such a case due to space-time constraint the waveform of the sound adjust themselves so as to obey the law of conservation of energy.
<u>The apparent frequency of the sound for the observer is given by:</u>
....................................(1)
where:
observed frequency
original source frequency
speed of sound
speed of source relative to the observer (taken negative when approaching towards the observer and vice-versa)
speed of observer relative to the source (taken negative when moving away from the source and vice-versa)
<u>According to the given situation, eq. (1) becomes:</u>

Since, 
Therefore

Pitch is very closely related to the frequency, it means that how fast is the amplitude of sound varying with time.
D. It is thermal conductivity because to work as a tool to heat things up it needs to conduct its temperature
Answer:
t = 4.0 min
Explanation:
given data:
diameter of rod = 2 cm
T_1 = 100 degree celcius
Air stream temperature = 20 degree celcius
heat transfer coefficient = 200 W/m2. K
WE KNOW THAT
copper thermal conductivity = k = 401 W/m °C
copper specific heat Cp = 385 J/kg.°C
density of copper = 8933 kg/m3
charateristic length is given as Lc




Biot number is given as 

Bi = 0.0025
As Bi is greater than 0.1 therefore lumped system analysis is applicable
so we have
............1
where b is given as



b = 0.01163 s^{-1}
putting value in equation 1

solving for t we get
t = 4.0 min
Answer:
Nicolaus Copernicus
Explanation:
With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it.