A. If an objects velocity is decreasing, the object is said to be decelerating not accelerating.
B. If an objects velocity changes, it is either experiencing acceleration or deceleration
C. If an object is said to be decelerating, its velocity must be decreasing.
D. If an objects velocity remains constant, its acceleration is zero.
∴ B is correct
Positive ion with a radius smaller than the radius of the atom
The specific heat of water is higher than the specific heat of concrete.
The density is calculated as mass per volume, so if we want to solve for mass, we would multiply density by volume.
For Part A: if we have a density of 0.69 g/mL, and a volume of 280 mL, multiplying these will give a mass of: (0.69 g/mL)(280 mL) = 193.2 g. Rounded to 2 significant figures, this is 190 g gasoline.
For Part B: if we have a density of 0.79 g/mL, and a volume of 190 mL, multiplying these will give a mass of: (0.79 g/mL)(190 mL) = 150.1 g. Rounded to 2 significant figures, this is equal to 150 g ethanol.