a black sphere with a diameter of 25 cm is suspended in air what is the surface temperature necessary to heat 10 kg of air what is the wavelength at the peak intensity

Which best describes how fluids change as they travel through different portions of the convection currents? they change to solids at the outer portion of the convection currents. they change to solids at the inner portion of the convection currents. they become more dense at the outer portion of the convection currents. they become more dense at the inner portion of the convection currents

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up