A subway train travels between two of its station stops with the acceleration schedule shown. Determine the time interval Δ t during which the train brakes to a stop with a deceleration of 2m/s 2 and find distance ‘s’ between stations.
Text Solution
Verified by ExpertsCHECK THE SOLUTION
Sol. Area under graph gives change in velocity
Train starts from rest and comes to rest
Therefore,
Positive area = negative area
8 × 1 + 6 × 2 = 2 × Δ t
8 + 12 = 2 Δ t
Δ t = 
= 10sec .
Displacement & distance are equal in this case displacement can be directly calculated from at curve without using v-t curve as follows
Δ S = ut 0 + (area under a-t curve) (t 0 – t c )
Where u → initial velocity
t 0 → total time
t c → abscissa of centroid of corresponding area
Δ s = 8 [34 – 4] + 12 [34–11] + (–20) [34–29]
= 8 × 30 + 12 × 23 – 20 × 5
= 240 + 276 – 100
= 516 – 100
Δ s = 416m.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems