The angle of a vector makes with the x-axis of a coordinate system mush be what size in order to make one or more of its components negative?
Less than 30 degrees
Between 30 and 60 degrees
Between 61 and 90 degrees
Greater than 90 degrees

What makes thermal imaging cameras useful? they can detect differences in color. they can detect differences in wave speeds. they can detect differences in temperature. they can detect mechanical waves.

Which of these activities increases the amount of carbon in the atmosphere?

Along wire of diameter 1 mm is submerged in an oil bath of temperature ∞ 31°c. the wire has an electrical resistance per unit length of 0.01 ω/m. if a current of 103 a flows through the wire and the convection coefficient is 500 w/m2·k, what is the steady-state temperature of the wire? from the time the current is applied, how long does it take for the wire to reach a temperature that is within 1°c of the steady-state value? the properties of the wire are 8000 kg/m3, 500 j/kg·k, and 20 w/m·k.