travelling at a constant speed of 11.8 m s1.While running at a constant speed he was also accelerating. Justify that statement.
(vi) The dimensions of the running track are illustrated in Fig 2.27. Calculate the displacement (correct to the nearest metre and degree) of a sprinter, on the inside lane, from his start position to the point where he crosses the finish line.
(4) (9)
‘SECTION B’
HALF QUESTION Typical of Question 12 in Leaving Cert. Exam
Q5 Answer both of the following parts (a) and (b).
(a) What is the difference between vector quantities and scalar quantities and give one example of each. (9)
A cyclist travels from A to B along the ‘S’ shaped path as illustrated in Fig 2.28.The arc of the circular sections have radius 20 m as shown. Calculate: (i) the distance travelled (ii) the displacement undergone by the cyclist (12) If the cyclist travels at 16 m s1, how long does it take to get from A to B?
(b) A car travelling 45 km h1 applies the breaks and decelerates at 8 m s2. (i) What is its initial velocity in metres per second? (ii) What distance does it travel in coming to rest?
(iii) If the initial velocity of the car is doubled, how much further does the car travel? Give your answer in metres and then as a factor of the original distance.
(c) Derive the relationship between displacement, initial velocity, final velocity and acceleration for a body travelling under linear motion.
Describe an experiment to find the resultant of two vectors. 20 m B Fig 2.28 (7) (6) (12) (10)
