12
47) Because of the high heat and low humidity in the summer in Death Valley, California, a
visitor requires about one quart of water for every two miles traveled on foot. If the density of
water is 0.990 g/mL at 45°C, how many kilograms of water are required for a person to walk 30
kilometers in Death Valley?
A) 8.7 kg
B) 70 kg
C) 3.5 × 102 kg
D) 7.0 × 102 kg
48) Specific gravity of a liquid is often defined as the ratio of the density of a substance to the
density of water. If the specific gravity of X relative to water is 0.800 and the specific gravity of
Y relative to water is 1.50, which of the following statements is false?
A) If X is a liquid, Y will float on X.
B) If X is a solid, X will float in water.
C) If Y is a liquid, water will float on Y.
D) If Y is a liquid, X will float in Y.
49) A piece of plastic weighing 1.157 g has a volume of 1.48 cm3. A piece of wood has the same
volume but weighs 3.85 g. The density of liquid X is 0.765 g/mL and the density of liquid Z is
1.13 g/mL. The two liquids are immiscible. If the plastic and wood are added to the two liquids,
what is the order of layers from top to bottom in the container?
A) liquid X, liquid Z, plastic, wood
B) liquid X, plastic, liquid Z, wood
C) plastic, wood, liquid Z, liquid X
D) wood, liquid Z, plastic, liquid X
50) Calculate the kinetic energy of a 150-g baseball moving at a speed of 40. m/s (89 mph).
K. E. = .
A) 6.0 J
B) 1.2 × 102 J
C) 6.0 × 103 J
D) 1.2 × 105 J
51) The average mass of an oxygen atom is 5.3 × 10-26 kg. Calculate the kinetic energy of a