Question

1. if the balance was not tared to display 0.00 g prior to adding the cube, which of the following statements are true? select all that apply. a. the mass displayed by the balance is the mass of the cube. b. no calculation is needed to determine the mass of the cube. c. the mass of the cube can be calculated. the mass displayed on the balance before the cube was added will need to be subtracted from the mass displayed on the balance with the cube. d. the cube can be reweighed after the balance has been tared to display 0.00 g.

Explanation:

When a balance is not tared (zeroed) before adding the cube, the initial non - zero reading (\(0.00\ g\) in this case) means that the mass of the cube is not directly the displayed value.

• Option A: Since the balance wasn't tared initially (displayed \(0.00\ g\) which is incorrect for a zero - point), the displayed mass is not the true mass of the cube. So, this option is false.
• Option B: We need to calculate the mass. If the balance had a non - zero reading before adding the cube (even if it was \(0.00\ g\) incorrectly), we need to consider the change in reading. So, calculation is needed, and this option is false.
• Option C: Let the mass of the cube be \(m\), the initial reading (before adding the cube) be \(m_1\) (here \(m_1 = 0.00\ g\) but it should be \(0\ g\) for a properly tared balance). After adding the cube, the reading is \(m_2\). Then \(m=m_2 - m_1\). So, the mass of the cube is calculated by subtracting the initial (incorrect \(0.00\ g\)) reading from the final reading. This option is true.
• Option D: Taring the balance (resetting it to \(0\ g\) properly) allows for re - weighing. After taring (correcting the zero - point), the cube can be reweighed. This option is true.

Answer:

C. The mass of the cube can be calculated. The mass displayed on the balance before the cube was added will need to be subtracted from the mass displayed on the balance with the cube.
D. The cube can be reweighed after the balance has been tared to display \(0.00\ g\).