Answer:
see explanation below
Explanation:
Given that,
500°C
= 25°C
d = 0.2m
L = 10mm = 0.01m
U₀ = 2m/s
Calculate average temperature

262.5 + 273
= 535.5K
From properties of air table A-4 corresponding to
= 535.5K 
k = 43.9 × 10⁻³W/m.k
v = 47.57 × 10⁻⁶ m²/s

A)
Number for the first strips is equal to


Calculating heat transfer coefficient from the first strip


The rate of convection heat transfer from the first strip is

The rate of convection heat transfer from the fifth trip is equal to


Calculating 

The rate of convection heat transfer from the tenth strip is


Calculating

Calculating the rate of convection heat transfer from the tenth strip

The rate of convection heat transfer from 25th strip is equal to

Calculating 

Calculating 

Calculating the rate of convection heat transfer from the tenth strip

Answer:
ΔE = 8.77 × 10¹¹ J
Explanation:
given,
²¹⁴₈₄Po -----> ²¹⁰₈₂Pb + 42 He
Atomic masses: Pb-210 = 209.98284 amu
Po-214 = 213.99519 amu
He-4 = 4.00260 amu
1 kg = 6.022 × 10²⁶ amu;
NA = 6.022 × 10²³ mol⁻¹
c = 2.99792458 × 10⁸ m/s
energy of molecule using equation
ΔE = Δm c²
Δm is mass difference and c is speed of light
Δm = 209.98284 + 4.00260 - 213.99519
Δm = - 0.00975 amu
1 amu = 1.66 x 10⁻²⁷ kg
- 0.00975 amu = - 0.00975 x 1.66 x 10⁻²⁷ Kg
= -0.016185 x 10⁻²⁷ Kg
total mass = 6.022 × 10²³ x -0.016185 x 10⁻²⁷
= -0.097467 x 10⁻⁴ Kg
ΔE = -(0.097467 x 10⁻⁴) (3 x 10^8)²
ΔE = - 8.77 × 10¹¹
ΔE = 8.77 × 10¹¹ J
Answer:
45km/hr
Explanation:
Total distance=450km
Total speed=50km/hr
Total time= distance/speed
=450/50
=9hrs
distance a=180km
speed a=60km/hr
Time a=180/60
=3hrs
Distance b=450-180=270km
Speed b=?
Time b=270/speed b
Total time=time a + time b
9=3+(270/speed b)
270/speed b =9-3
270/speed b =6
6*speed b =270
Speed b=270/6
Speed b=45km/hr
Given that,
The electric field is given by,

Suppose, B is the amplitude of magnetic field vector.
We need to find the complete expression for the magnetic field vector of the wave
Using formula of magnetic field
Direction of
vector is the direction of propagation of the wave .
Direction of magnetic field = 

We need to calculate the poynting vector
Using formula of poynting

Put the value into the formula


Hence, The poynting vector is 
496/1127 = 0.44 = 44%
<span>sin A = 0.85/2.1. </span>
<span>A = 23.9o. </span>
<span>Fp = 1127 sin23.9 = 457 N. = Force parallel to the ramp. </span>
<span>Fn = 1127 Cos23.9 = 1,030 N. = Force </span>
<span>perpendicular to the ramp = Normal force. </span>
<span>Eff. = Fp/Fap = 457/496 = 0.92 = 92%
Correct answer: 92%</span>