Only a 1-meter cube is a unit cube and the correct option is B.
A unit cube is a cube whose sides are all equal to 1 unit. Analyzing the options:
Option A: 7 feet is not considered a unit in any common measurement system.
Option B: 1 meter is a standard unit of length. If the cube has sides of 1 meter each, it would be a unit cube.
Option C: 5 inches is not a standard unit of length in the metric system, making it unlikely for the cube to be a unit cube.
Option D: 15 centimeters is not a standard unit of length, and even if it was, 15 units wouldn't qualify as a unit cube.
Therefore, the only cube that could be a unit cube is option B.
Question:
Which cube is a unit cube?
A. cube that is 7 feet long, 7 feet tall, and 7 feet high
B. a cube that is 1 meter long, 1 meter wide, and 1 meter high
C. a cube that is 5 inches long, 5 inches wide, and 5 inches high
D. a cube that is 15 centimeters long, 15 centimeters wide, and 15 centimeters high