Answer:
time required for cooling process = 0.233 hours
Explanation:
In Transient heat conduction of a Sphere, the formula for Biot number is;
Bi = hL_c/k
Where L_c = radius/3
We are given;
Diameter = 12mm = 0.012m
Radius = 0.006m
h = 20 W/m²
k = 40 W/m·K
So L_c = 0.006m/3 = 0.002m
So,Bi = 20 x 0.002/40
Bi = 0.001
The formula for time required is given as;
t = (ρVc/hA)•In[(T_i - T_(∞))/(T - T_(∞))]
Where;
A is Area = πD²
V is volume = πD³/6
So,
t = (ρ(πD³/6)c/h(πD²))•In[(T_i - T_(∞))/(T - T_(∞))]
t = (ρDc/6h)•In[(T_i - T_(∞))/(T - T_(∞))]
We are given;
T_i = 1200K
T_(∞) = 300K
T = 450K
ρ = 7800 kg/m³
c = 600 J/kg·K
Thus, plugging in relevant values;
t = (7800 x 0.012 x 600/(6 x20) )•In[(1200 - 300)/(450 - 300)]
t = 468•In6
t = 838.54 seconds
Converting to hours,
t = 838.54/3600
t = 0.233 hours
Answer:
-50.22kJ
Explanation:
Given:
Initial state Temperature =300k
Pressure 1= 150kPa
Pressure 2 = 800kPa
Volume 1 = 0.2m^3
Work done = Pressure 1 × Volume 1 × (inverse of pressure 1 ÷ pressure 2)
= 150kPa × 0.2m^3 × (inv 150 kPa ÷800 kPa)
= - 50.22kJ
Answer:
74 Ω
Explanation:
Data provided in the question:
Maximum value of the current that can be provided = 500 mA
= 500 × 10⁻³ A
Applied voltage set for the system = 37 V
Now,
The smallest resistance that can be measured
= [ Applied voltage ] ÷ [ Maximum current that can be applied ]
= 37 ÷ ( 500 × 10⁻³ )
= 74 Ω
Answer:
Can you give me a brainlest?? :(
Explanation: