A child pulls a 15kg sled containing a 5.0 kg dog along a straight path on a horizontal surface. He exerts a force pf 55 N on the sled at an angle of 20 above the horizontal, as shown in the figure above. The coefficient of friction between the sled and the surface is 0.22.

Diamond will scratch quartz. true or false

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? a. the ice dissolves oxygen from the air, forming a denser crystalline matrix.b. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds.c. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer.d. the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer.

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.