A cyclist is standing still at the top of the hill and begins to coast down the hill. The mass of the cyclist and bike is 64 kg. the cyclist gravitational potential energy is converted into kinetic energy with an efficiency of 48%. What is her speed when she reaches a point that is a vertical distance 12 m lower than the point at which she started

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.