How the tapes are made
Each tape comes from an invented run: a trolley speeding up, slowing down or rolling steadily, a falling mass, or two trolleys colliding. The run is built so that every section you are asked to measure has a whole number of millimetres, and the dots never sit closer than 2.5 mm. A ruler reading can be 1 mm out, so lengths within 1 mm are right, and every speed or acceleration you work out from them is right anywhere in the range those readings give.
Measuring on paper
Tapes print at full size, in pieces of up to 15.5 cm, each with a ruler whose 0 sits on the piece’s first dot. Choose “Use your own ruler” to leave the printed ruler off. Every sheet has a 10 cm bar: if it does not measure 10.0 cm, print again at 100% (Actual size). On a phone the tape opens wide enough to read the millimetre marks: slide it sideways, or tap Fit to screen to see it whole.
A worked example
In set TAPE9X the first tape speeds up steadily. Dots A and B are 15 ticks apart, so A to B took 15 × 0.02 = 0.3 s. A to B measures 120 mm, so the mean speed was 120 ÷ 0.3 = 400 mm/s, or 0.40 m/s. In question 4, 5-tick sections P and Q measure 29 mm and 41 mm: 0.29 m/s and 0.41 m/s. Their middles are 10 ticks (0.2 s) apart, so a = (0.41 − 0.29) ÷ 0.2 = 0.6 m/s².
Questions
What is the time between two dots on a ticker tape?
One tick: 1 ÷ the timer's frequency. A 50 Hz timer makes 50 dots a second, so each gap is 0.02 s; at 60 Hz it is 1/60 s. Count the gaps, not the dots: 11 dots in a row have 10 gaps, which is 0.2 s at 50 Hz.
How do you find speed from a ticker tape?
Measure a section and divide by its time. A 5-tick section of 46 mm at 50 Hz took 5 × 0.02 = 0.1 s, so the mean speed was 46 mm ÷ 0.1 s = 460 mm/s, or 0.46 m/s. That speed belongs to the middle of the section.
How do you find acceleration from a ticker tape?
Find the mean speed of two equal sections, then divide the change by the time between their middles: a = (v − u) ÷ t. Two 5-tick sections at 0.29 and 0.41 m/s with their middles 10 ticks (0.2 s) apart give (0.41 − 0.29) ÷ 0.2 = 0.6 m/s². Slowing down gives a negative answer.
What is a ticker tape chart?
The tape cut into strips of equal time (5 or 10 ticks) and stood side by side in order. Each strip's length is proportional to its mean speed, so the chart is a velocity-time graph: a straight sloping top means steady acceleration, and the total area is the distance travelled.
How do you find g with a ticker timer?
Let a mass fall and pull a tape through the timer. Find the speed of two short sections and divide the change by the time between their middles. Friction at the timer and air resistance slow the fall, so the answer comes out a little under 9.8 m/s².
My answer is a little different from the key. Is it wrong?
Probably not. A careful ruler reading can be 1 mm out, so lengths within 1 mm count as right, and speeds, accelerations and momentum count as right anywhere in the range those readings give. The key prints that range in brackets.
Sources, checked October 25, 2026: Department of Basic Education, CAPS Physical Sciences Grades 10 to 12 (2011), the Grade 10 trolley and ticker tape project and Grade 11 and 12 ticker timer experiments for g; AQA GCSE Physics 8463 specification, version 1.1 (September 30, 2019, PDF), 4.5.7.2 collisions with ticker timers; schoolphysics, Ticker timer introduction (Keith Gibbs), five-space strips and the time between pieces; Mini Physics, Ticker Tape Timer, gaps not dots and mid-times.