An MRT train accelerates uniformly from rest to a speed of 20m/s in 10 seconds. it travels at this speed for the next 30 secs before the driver suddenly applies the emergency brake. the train decelerates uniformly to rest in a further 5 secs.
a.calculate the acceleration of the train
b.calculate the deceleration
c.calculate the total distance traveled
d.find the average speed of the train
for a, my working is (20-0)/10 = 2m/s-2
for b, i did (0-20)/5 = -4m/s-2 , so deceleration is 4.
for c,
0.5 X 20 X 10 = 100
20X30=600
0.5X5X10 = 50
total dist = 750 ( I VISUALISE IT IN GRAPH STYLE)
and d.
750/45 = 16.67m/s-1
i think i did wrongly for part c and d. could someone help me identify?
answer for part c correct
alternatively, you might want to use the following equation to help you
s=ut + 1/2 a t^2
Then don't need to visualise le...
And since for part c correct, part d is also correct