Achild in a boat throws a 5.10-kg package out horizontally with a speed of 10.0 m/s. the mass of the child is 27.6 kg and the mass of the boat is 34.2 kg calculate the velocity of the boat immediately after, assuming it was initially at rest.

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.