A solar collector consists of a long duct through which air is blown; its cross section forms an equilateral triangle 1 m on a side. One side consists of a glass cover of emissivity 0.9, while the other two sides are absorber plates with 1.0. Illustration shows a equilateral triangle, with one side protected by a glass cover and the other two sides protected by absorber plates. During operation the surface temperatures are known to be 25°C, 60°C, and 80°C. What is the net rate at which radiation is transferred to the cover due to exchange with the absorber plates, in W/m?

We want to calculate the total metabolic heat generated by a singing canary taking into account heat transfer by radiation, convection and exhaling air. the air temperature is 20 oc, canary’s body internal and surface temperature is 33oc, external body surface convective heat transfer coefficient is 25.2 w/m2 .k, temperature difference between the inhaled and exhaled air is 4.3 oc, the ventilation rate is 0.74 cc of air per second, specific heat of air is 1.0066 kj/kg. k and density of air is 1.16 kg/m3 . assume the canary’s body to be a cylinder with 7 cm diameter and 9 cm length, and heat exchange is from the side as well as the top and bottom of cylinder. calculate 1) the net rate of heat lost by radiation, assuming heat gained by the bird through radiation from the surroundings is 11.5 w; 2) rate of heat transferred by convection to the surrounding air; 3) rate of heat transferred in the exhaling air without considering any internal evaporation; 4) total metabolic power.

Heterogeneous mixture with larger particles that never settle is

A1.5m wire carries a 2 a current when a potential difference of 52 v is applied. what is the resistance of the wire?