If the thickness of the coating is 2.5 mm and it has an initial uniform temperature of 200ºc, how long will it take for the surface to achieve a safe-to-touch temperature of 38ºc if the convection coefficient is 200 w/m2·k? what is the corresponding value of the interface temperature? the thermal conductivity and diffusivity of the plastic are 0.25 w/m·k and 1.20 × 10-7 m2/s, respectively.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.

The dipole moment of the water molecule (h2o) is 6.17x10^-30 c.m. consider a water molecule located at the origin whose dipole moment p points in the +x-direction. a chlorine ion ( of charge-1.60x10^-19c , is located at x=3.00x10^-9m . assume that is much larger than the separation d between the charges in the dipole, so that the approximate expression for the electric field along the dipole axis can be used. a) find the magnitude of the electric force that the water molecule exerts on the chlorine ion. b) what is the direction of the electric force. -x-direction or +x-direction c) is this force attractive or repulsive?

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.