1 3.1.4 Quiz: Noncontact Forces Question 3 of 10
Two particles are separated by 0.38 m and have charges of -6.25 x 10-°C
and 2.91 x 10-9C. Use Coulomb's law to predict the force between the
particles if the distance is doubled. The equation for Coulomb's law is
Fe = kq,92, and the constant, k, equals 9.00 x 109 Nm2/C2
A. -2.83 x 10-7N
B. 2,83 x 10-7N
C. -1.13 x 10-6N
D. 1.13 x 10-6N
SUBMIT

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.