Arubber ball is dropped and bounces vertically from a horizontal concrete floor. if the ball has a speed of 3 m/s just before striking the floor, and a speed of 6.5 m/s just after bouncing, find the average force of the floor on the ball. assume that the ball is in contact with the floor for 0.32 s, and that the mass of the ball is 0.42 kg

Which of the following represents an upside-down image?

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 component of the earth’s atmosphere is decreased due to photosynthesis?