Question

1. what is the name for the instrument below?

a) graduated cylinder
c) beaker
b) post cylinder
d) test tube

1. describe the dart locations below...

a) accurate and precise
c) accurate, not precise
b) precise, not accurate
d) not accurate or precise

1. if you need to measure 115ml of water you should use what instrument?

a) 150ml beaker
c) 100ml graduated cylinder
b) test tube
d) 100ml beaker

1. density can be expressed in which units?

a) g/cm³
c) cm/kg
b) g/kg
d) kg/ml³

1. measurements are always uncertain because...

a) both (b) and (c)
b) instruments are never perfect
c) measurements always involve some estimation
d) people dont know how to use instruments

Explanation:

• Question 33: A test tube is a narrow - necked container, often used in laboratories. A graduated cylinder has markings for measuring volume, a beaker is wider and usually for mixing, and "post cylinder" is not a standard lab instrument.
• Question 34: Precision refers to how close measurements are to each other. Accuracy refers to how close measurements are to the true value. The darts are close to each other (precise) but not near the center (not accurate).
• Question 35: A 150mL beaker can hold 115mL of water. A 100mL graduated cylinder or beaker cannot hold 115mL. A test tube is not for measuring such a volume.
• Question 36: Density is mass per unit volume. \(g/cm^{3}\) is a common unit for density (\(g\) is mass, \(cm^{3}\) is volume). \(g/kg\) is a mass - to - mass ratio, \(cm/kg\) is a length - to - mass ratio, and \(kg/mL^{3}\) is an incorrect unit combination.
• Question 37: Measurements are uncertain because instruments have limitations (not perfect) and measurements often require some estimation (e.g., reading between markings). If people don't know how to use instruments, that's user error, not inherent measurement uncertainty.

Answer:

1. d) test tube
2. b) precise, not accurate
3. a) 150mL beaker
4. a) \(g/cm^{3}\)
5. a) both (b) and (c)