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Ticker Tape
Ticker Timer
- A ticker-timer consists of an electrical vibrator which vibrates 50 times per second.
- This enables it to make 50 dots per second on a ticker-tape being pulled through it.
- The time interval between two adjacent dots on the ticker-tape is called one tick.
- One tick is equal to 1/50 s or 0.02 s.
Diagram 2.4 shows a strip of ticker tape that was pulled through a ticker tape timer that vibrated at 50 times a second. What is the
- time taken from the first dot to the last dot?
- average velocity of the object that is represented by the ticker tape?
Answer:
a.
There are 15 ticks from the first dot to the last dot, hence
Time taken = 15 × 0.02s = 0.3s
b.
Distance travelled = 15cm
$\begin{gathered}
v = \frac{s}
{t} \hfill \\
v = \frac{{15cm}}
{{0.3s}} = 50cms^{ - 1} \hfill \\
\end{gathered} $
The ticker-tape in figure above was produced by a toy car moving down a tilted runway. If the ticker-tape timer produced 50 dots per second, find the acceleration of the toy car.
Answer:
In order to find the acceleration, we need to determine the initial velocity, the final velocity and the time taken for the velocity change.
Initial velocity,
u = \frac{s}
{t} = \frac{{3cm}}
{{0.02s}} = 150cms^{ - 1}
v = \frac{s}
{t} = \frac{{0.5cm}}
{{0.02s}} = 25cms^{ - 1}
Time taken for the velocity change,
t = (0.5 + 4 + 0.5) ticks = 5 ticks
t = 5 × 0.02s = 0.1s
Acceleration,
a = \frac{{v - u}}
{t} = \frac{{25 - 150}}
{{0.1}} = - 1250cms^{ - 1}
A trolley is pushed up a slope. Diagram above shows ticker tape chart that show the movement of the trolley. Every section of the tape contains 5 ticks. If the ticker-tape timer produced 50 dots per second, determine the acceleration of the trolley.
Answer:
In order to find the acceleration, we need to determine the initial velocity, the final velocity and the time taken for the velocity change.
Initial velocity,
u = \frac{s}
{t} = \frac{{5cm}}
{{5 × 0.02s}} = 50cms^{ - 1}
v = \frac{s}
{t} = \frac{{1cm}}
{{5 × 0.02s}} = 10cms^{ - 1}
Time taken for the velocity change,
t = (2.5 + 5 + 5 + 5 + 2.5) ticks = 40 ticks
t = 40 × 0.02s = 0.8s
Acceleration,
a = \frac{{v - u}}
{t} = \frac{{10 - 50}}
{{0.8}} = - 50cms^{ - 1}
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