In: Advanced Math
(2) PQRS is a quadrilateral and M is the midpoint of PS.
PQ = a, QR = b and SQ = a – 2b.
(a) Show that PS = 2b.
Answer(a)
[1]
(b) Write down the mathematical name for the quadrilateral PQRM,
giving reasons for your answer.
Answer(b)
..............................................................
because
...............................................................
.............................................................................................................................................................
[2]
__________
A tram leaves a station and accelerates for 2 minutes until it
reaches a speed of 12 metres per second.
It continues at this speed for 1 minute.
It then decelerates for 3 minutes until it stops at the next
station.
The diagram shows the speed-time graph for this journey.
Calculate the distance, in metres, between the two stations
1.
a)
Let
By triangle law of vectors,
b)
Also,
since, and
Hence, PQRM must be a isosceles trapezium.
2)
Let the distance covered in the first 2 minutes be x1,
acceleration of the tram will be,
in the next 1 minute it continues to move uniformly with v=12m/s, hence
In the next 3 minutes, it decelerates to rest so deceleration would be,
Therefore, the total distance travelled will be,