When the light from the sun warms the ground, the transfer of energy of heat is a) conduction b) power c) radiation d) reflection

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

Aplane's average speed between two cities is 600 km/h. if the trip takes 2.5 hours, how far does the plane fly?

Asquare isothermal chip is of width w=5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated; the front surface is exposed to the flow of a coolant at tinf=15 °c. from reliability considerations, the chip temperature must not exceed t=85 °c. if the coolant is air and the corresponding convection coefficient is h=200 w/m2 x k, what is the maximum allowable "power" of the chip? if the coolant is a liquid for which h=3000 w/m2 x k, what is the maximum allowable power of the chip?