Kate gathered three boxes of the same size made of different materials: glass, clear plastic, and aluminum painted black. she placed them on a window sill in the sun for an hour and then measured the warmth of the air in the box. in this experiment, the time of the hour is a(
a. constant
b. dependent variable
c. independent variable
d. control

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron

Ice at 0.0∘c has a density of 917 kg/m3. a 3.00 cm3 ice cube is gently released inside a small container filled with oil and is observed to be neutrally buoyant. what is the density of the oil?