Linda runs at a speed of 4.0 m/s and dives on a sled, initially at rost on the top of a frictionless, snow- covered hill. After she has descended a vertical distance of 5.0 m, her brother, who is initially at rest, hops
on her back, and they continue down the hill together. What is their speed at the bottom of the hill if the
otal vertical drop is 15.0 m? Linda's mass is 50 kg, the sled has a mass of 5.0 kg, and her brother has a
mass of 30 kg

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies. molten iron has a density of 7.0g/cm cubed. in its solid state, iron has a density of 8.0g/cm cubed.

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.

The most important difference between a wedge and an inclined plane is a. their size b. their shape c. how they are used d. what they are made of