Answer:
The first thing he would do is SUBTRACTION
Explanation:
Reason: The subtraction part would be in parenthesis so that causes us to do subtraction first
Here is a little help
P- Parenthesis
E- Exponents
M- Multiplication
D- Division
A- Addition
S- Subtraction
Since the subtraction is in parenthesis you would subtract first
Answer:
Un motor de paso es un motor eléctrico CC sin escobillas que divide una rotación completa en varios pasos iguales. Rota una distancia incremental específica por cada paso. El número de pasos que se ejecutan controla el grado de rotación del eje del motor.
Los motores de paso tienen cierta capacidad inherente para controlar la posición, ya que tienen pasos de salida integrados. Pueden controlar con gran precisión cuán lejos y cuán rápido rotará el motor de paso. El número de pasos que ejecuta el motor es igual al número de comandos de pulsos del controlador. Un motor de paso rotará una distancia y a una velocidad proporcional al número de la frecuencia de sus comandos de pulso.
Explanation:
Given Information:
Initial temperature of aluminum block = 26.5°C
Heat flux = 4000 w/m²
Time = 2112 seconds
Time = 30 minutes = 30*60 = 1800 seconds
Required Information:
Rise in surface temperature = ?
Answer:
Rise in surface temperature = 8.6 °C after 2112 seconds
Rise in surface temperature = 8 °C after 30 minutes
Explanation:
The surface temperature of the aluminum block is given by
![T_{surface} = T_{initial} + \frac{q}{k} \sqrt{\frac{4\alpha t}{\pi} }](https://tex.z-dn.net/?f=T_%7Bsurface%7D%20%3D%20T_%7Binitial%7D%20%2B%20%5Cfrac%7Bq%7D%7Bk%7D%20%5Csqrt%7B%5Cfrac%7B4%5Calpha%20t%7D%7B%5Cpi%7D%20%7D)
Where q is the heat flux supplied to aluminum block, k is the conductivity of pure aluminum and α is the diffusivity of pure aluminum.
After t = 2112 sec:
![T_{surface} = 26.5 + \frac{4000}{237} \sqrt{\frac{4(9.71\times 10^{-5}) (2112)}{\pi} }\\\\T_{surface} = 26.5 + \frac{4000}{237} (0.51098)\\\\T_{surface} = 26.5 + 8.6\\\\T_{surface} = 35.1\\\\](https://tex.z-dn.net/?f=T_%7Bsurface%7D%20%3D%2026.5%20%2B%20%5Cfrac%7B4000%7D%7B237%7D%20%5Csqrt%7B%5Cfrac%7B4%289.71%5Ctimes%2010%5E%7B-5%7D%29%20%282112%29%7D%7B%5Cpi%7D%20%7D%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2026.5%20%2B%20%5Cfrac%7B4000%7D%7B237%7D%20%280.51098%29%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2026.5%20%2B%208.6%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2035.1%5C%5C%5C%5C)
The rise in the surface temperature is
Rise = 35.1 - 26.5 = 8.6 °C
Therefore, the surface temperature of the block will rise by 8.6 °C after 2112 seconds.
After t = 30 mins:
![T_{surface} = 26.5 + \frac{4000}{237} \sqrt{\frac{4(9.71\times 10^{-5}) (1800)}{\pi} }\\\\T_{surface} = 26.5 + \frac{4000}{237} (0.4717)\\\\T_{surface} = 26.5 + 7.96\\\\T_{surface} = 34.5\\\\](https://tex.z-dn.net/?f=T_%7Bsurface%7D%20%3D%2026.5%20%2B%20%5Cfrac%7B4000%7D%7B237%7D%20%5Csqrt%7B%5Cfrac%7B4%289.71%5Ctimes%2010%5E%7B-5%7D%29%20%281800%29%7D%7B%5Cpi%7D%20%7D%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2026.5%20%2B%20%5Cfrac%7B4000%7D%7B237%7D%20%280.4717%29%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2026.5%20%2B%207.96%5C%5C%5C%5CT_%7Bsurface%7D%20%3D%2034.5%5C%5C%5C%5C)
The rise in the surface temperature is
Rise = 34.5 - 26.5 = 8 °C
Therefore, the surface temperature of the block will rise by 8 °C after 30 minutes.