Power is the RATE at which energy changes or flows.
The unit of energy is the Joule, so a unit of power is the Joule/second.
That unit has the special name "<em>Watt</em>".
Your question is not necessarily a question. It's also a statement, You could write
"<em>Watt's the basic unit of the measurement of power</em>".
1. a. longitudinal waves.
There are two types of waves:
- Transverse waves: in transverse waves, the oscillations of the wave occur in a direction perpendicular to the direction of propagation of the wave
- Longitudinal waves: in longitudinal waves, the oscillations of the waves occur parallel to the direction in which the waves are travelling.
So, these types of waves are called longitudinal waves.
2. d. a medium
There are two types of waves:
- Electromagnetic waves: these waves are produced by the oscillations of electric and magnetic field, and they can travel both in a medium and also in a vacuum (they do not need a medium to propagate)
- Mechanical waves: these waves are produced by the oscillations of the particles in a medium, so they need a medium to propagate - therefore, the correct choice is d. a medium
3. a. AM/FM radio
Analogue signals consist of continuous signals, which vary in a continuous range of values. On the contrary, digital signals consist of discrete signals, which can assume only some discrete values. For AM and FM radios, signals are transmitted by using analogue signals.
Answer
given,
time = 10 s
ship's speed = 5 Km/h
F = m a
a is the acceleration and m is mass.
In the first case
F₁=m x a₁
where a₁ = difference in velocity / time
F₁ is constant acceleration is also a constant.
Δv₁ = 5 x 0.278
Δv₁ = 1.39 m/s
![a_1=\dfrac{1.39}{10}](https://tex.z-dn.net/?f=a_1%3D%5Cdfrac%7B1.39%7D%7B10%7D)
a₁ = 0.139 m/s²
F₂ =m x a₂
F₃ = F₂ + F₁
Δv₃ = 19 x 0.278
Δv₃ = 5.282 m/s
a₃=Δv₂ / t
![a_3=\dfrac{5.282}{10}](https://tex.z-dn.net/?f=a_3%3D%5Cdfrac%7B5.282%7D%7B10%7D)
a₃ = 0.5282 m²/s
m a₃=m a₁ + m a₂
a₃ = a₂ + a₁
0.5282 = a₂ + 0.139
a₂=0.3892 m²/s
F₂ = m x 0.3892...........(1)
F₁ = m x 0.139...............(2)
F₂/F₁
ratio = ![\dfrac{0.3892}{0.139}](https://tex.z-dn.net/?f=%5Cdfrac%7B0.3892%7D%7B0.139%7D)
ratio = 2.8
Answer:
![\displaystyle \rho=1.25\ g/ml](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Crho%3D1.25%5C%20g%2Fml)
Explanation:
<u>Density
</u>
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:
![\displaystyle \rho=\frac{m}{V}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Crho%3D%5Cfrac%7Bm%7D%7BV%7D)
The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:
![\displaystyle \rho=\frac{3.75\ g}{3\ ml}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Crho%3D%5Cfrac%7B3.75%5C%20g%7D%7B3%5C%20ml%7D)
![\boxed{\displaystyle \rho=1.25\ g/ml}](https://tex.z-dn.net/?f=%5Cboxed%7B%5Cdisplaystyle%20%5Crho%3D1.25%5C%20g%2Fml%7D)
Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:
![\displaystyle \rho=1.25\ kg/l](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Crho%3D1.25%5C%20kg%2Fl)