When you drop a 0.45 kg apple, Earth ex- erts a force on it that accelerates it at 9.8 m/s?
toward the earth's surface. According to New
ton's third law, the apple must exert an equal
but opposite force on Earth
If the mass of the earth 3.98 x 1024 kg, what
is the magnitude of the earth's acceleration
toward the apple?
Answer in units of m/s

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.