Answer:
![60 {ms}^{ - 2}](https://tex.z-dn.net/?f=60%20%7Bms%7D%5E%7B%20-%202%7D%20)
Explanation:
As we know,
=》Force = Mass × Acceleration
=》45 N = 0.75 × Acceleration
=》Acceleration = 45 ÷ 0.75
=》Acceleration = 60
hence, the Acceleration of the ball would be. 60 meters per second square
![60m {s}^{ - 2}](https://tex.z-dn.net/?f=60m%20%7Bs%7D%5E%7B%20-%202%7D%20)
Solution :
Given :
Rectangular wingspan
Length,L = 17.5 m
Chord, c = 3 m
Free stream velocity of flow,
= 200 m/s
Given that the flow is laminar.
![$Re_L=\frac{\rho V L}{\mu _{\infty}}$](https://tex.z-dn.net/?f=%24Re_L%3D%5Cfrac%7B%5Crho%20V%20L%7D%7B%5Cmu%20_%7B%5Cinfty%7D%7D%24)
![$=\frac{1.225 \times 200 \times 3}{1.789 \times 10^{-5}}$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B1.225%20%5Ctimes%20200%20%5Ctimes%203%7D%7B1.789%20%5Ctimes%2010%5E%7B-5%7D%7D%24)
![$= 4.10 \times 10^7$](https://tex.z-dn.net/?f=%24%3D%204.10%20%5Ctimes%2010%5E7%24)
So boundary layer thickness,
![$\delta_{L} = \frac{5.2 L}{\sqrt{Re_L}}$](https://tex.z-dn.net/?f=%24%5Cdelta_%7BL%7D%20%3D%20%5Cfrac%7B5.2%20L%7D%7B%5Csqrt%7BRe_L%7D%7D%24)
![$\delta_{L} = \frac{5.2 \times 3}{\sqrt{4.1 \times 10^7}}$](https://tex.z-dn.net/?f=%24%5Cdelta_%7BL%7D%20%3D%20%5Cfrac%7B5.2%20%5Ctimes%203%7D%7B%5Csqrt%7B4.1%20%5Ctimes%2010%5E7%7D%7D%24)
= 0.0024 m
The dynamic pressure, ![$q_{\infty} =\frac{1}{2} \rho V^2_{\infty}$](https://tex.z-dn.net/?f=%24q_%7B%5Cinfty%7D%20%3D%5Cfrac%7B1%7D%7B2%7D%20%5Crho%20V%5E2_%7B%5Cinfty%7D%24)
![$ =\frac{1}{2} \times 1.225 \times 200^2$](https://tex.z-dn.net/?f=%24%20%3D%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%201.225%20%20%5Ctimes%20200%5E2%24)
![$=2.45 \times 10^4 \ N/m^2$](https://tex.z-dn.net/?f=%24%3D2.45%20%5Ctimes%2010%5E4%20%5C%20N%2Fm%5E2%24)
The skin friction drag co-efficient is given by
![$C_f = \frac{1.328}{\sqrt{Re_L}}$](https://tex.z-dn.net/?f=%24C_f%20%3D%20%5Cfrac%7B1.328%7D%7B%5Csqrt%7BRe_L%7D%7D%24)
![$=\frac{1.328}{\sqrt{4.1 \times 10^7}}$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B1.328%7D%7B%5Csqrt%7B4.1%20%5Ctimes%2010%5E7%7D%7D%24)
= 0.00021
![$D_{skinfriction} = \frac{1}{2} \rho V^2_{\infty}S C_f$](https://tex.z-dn.net/?f=%24D_%7Bskinfriction%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5Crho%20V%5E2_%7B%5Cinfty%7DS%20C_f%24)
![$=\frac{1}{2} \times 1.225 \times 200^2 \times 17.5 \times 3 \times 0.00021$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%201.225%20%5Ctimes%20200%5E2%20%5Ctimes%2017.5%20%5Ctimes%203%20%5Ctimes%200.00021%24)
= 270 N
Therefore the net drag = 270 x 2
= 540 N
Answer:
3 mA.
Explanation:
The following data were obtained from the question:
Resistor (R) = 500 Ω
Potential difference (V) = 1.5 V
Current (I) =.?
Using the ohm's law equation, we can obtain the current as follow:
V = IR
1.5 = I x 500
Divide both side by 500
I = 1.5 / 500
I = 3×10¯³ A.
Therefore, the current in the circuit is 3×10¯³ A.
Finally, we shall convert 3×10¯³ A to milliampere (mA).
This can be obtained as follow:
Recall:
1 A = 1000 mA
Therefore,
3×10¯³ A = 3×10¯³ × 1000 = 3 mA
Therefore, 3×10¯³ A is equivalent to 3 mA.
Thus, the current in mA flowing through the circuit is 3 mA.
The total mechanical energy of the notebook is <u><em>19J</em></u>.
Mechanical energy is the sum of potential energy and kinetic energy. It has no kinetic energy, because it's not moving. So its potential energy is all the mechanical energy it has.