is the thermal energy transferred in a refrigerator primarily by conduction, convection or radiation? explain your answer

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

Which accurately compares concave and convex lenses?

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656(red) and 486 (blue). light from a hydrogen lamp illuminates a diffraction grating with 500 lines per mm, and the light is observed on a screen 1.50 behind the grating. what is the distance between the first-order red and blue fringes?