No one knows how the legend of the Phantom Car of PIE began.
It is said that lousier drivers on the PIE every morning can sometimes hear the eerie squealing of tyres and the roar of an engine, accompanied by thumping techno music, that heralded the momentary appearance of a mysterious black car in their mirrors.
Eye witness accounts tell of a sexy slim lady with pale flawless complexion behind its wheel, with nary a spill from the paper cup of kopi peng perched on the cup-holder as she overtook from the left in one mesmerizing move, casting a bone-chilling glance of irritation as she passed.
During these moments, sleeping students being ferried to school in SUVs have been known to suddenly sit up and recite aloud trigonometry formulae, and taxi drivers have been reported to suddenly stop scolding the government and instead expound the applications of integration to their (disinterested) passengers.
All these, however, remain as an urban legend to a particular lorry driver cruising at a leisurely speed along the PIE’s right-most lane this morning, much to the annoyance of the long train of cars behind.
But it all changed when a vicious 100+ BPM techno track sounded from nowhere to drown out Teresa Teng‘s crooning voice in his stereo.
The needles in his instrument panel started to swing wildly, and all the denials in the world couldn’t prepare him from the blinding aura emanating from that innocuous-looking black car in his mirror …
Assuming the black car appeared right next to the lorry at t = 0, the diagram shows the speed-time graph of the lorry and the black car during a period of 60 seconds.
Find
- the acceleration of the car in the first 10 seconds;
- the distance travelled by the car during the 60 seconds;
- the distance travelled by the lorry during the 60 seconds;
- the time when the car overtakes the lorry (if it does), and the time when the lorry overtakes the car (if it does).
Distance covered = area under the graph
DON’T be confused with your average speed = total distance/total time formula you learnt in PSLE!
P.S. While many of Miss Loi’s Sec 3 students were smirking at her for insulting their intelligence when doing Parts 1-3, for some reason quite a number of them weren’t smirking anymore when they reached Part 4.
