1. Graph the equations of motion of two mobiles x 1 = 250-10t and x 2 = 15t and determine the time and the place of their meeting. (3 points)
2. The distance between two localities A and B is d = 50km. A mobile starts from A with speed v 1 = 20km / h, and al
the second mobile, with speed v 2 = 40km / h, starts from B, in the same direction as the first mobile, but at t 02 = 2h after
departure of the first mobile. The movements of the two mobiles are uniform rectilinear.
a) Write the laws of motion of the two mobiles, with respect to A.
b) Find the time and place of the meeting of the two mobiles, compared to A.

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.

Which feature of a heating curve indicates a change ofn state

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.