C6-L5-D4-USHNA-SCI-LQ

Multiple Choice

Why can’t a ruler measure a curved line correctly?

• It is too short

• A ruler is straight while the line is curved

• The numbers are confusing

• Curves don’t have length

Reorder

Arrange the steps of the thread method:

• Place thread along the curve

• Mark start and end points

• Straighten thread and measure with ruler

1

2

3

• 1
• 2
• 3

Open Ended

Give two examples of real-life objects where you would use the thread method.

Multiple Choice

Two students measure the same curved line with thread. One gets 12 cm, another 13 cm. Why?

• Curves don’t have exact length

• Thread was stretched differently

• One ruler had no numbers

• Chalk line disappeared

Multiple Choice

Which of these is a measurement error?

• Starting at zero

• Tilting the ruler

• Using SI units

• Looking straight above

Match

Match error → cause:

• Wrong start

• Tilted scale

• Parallax

Not starting at zero

Viewing from angle

Ruler not flat

• Not starting at zero

• Viewing from angle

• Ruler not flat

Open Ended

Write two ways to avoid measurement errors while using a ruler.

Multiple Choice

Parallax error happens when:

• You look from an angle instead of above

• You forget to use SI units

• You use thread incorrectly

• You use a broken ruler

Open Ended

In a car, the driver sees the speedometer needle at 60 km/h but the passenger sees 65 km/h. Why?

Multiple Choice

A student first measured a curve without starting at zero, then repeated correctly. Which measurement will be more accurate?

• First attempt

• Second attempt

• Both are same

• Neither