Question

A train starting from rest attains a velocity of 72 km h to the power - 1 in 5 minutes. Assuming that the acceleration is uniform, find (i) the acceleration and (ii) the distance travelled by the train for attaining this velocity. Using s = ut + 1/2 × at square

Answer 1

Sol. u =0

v =72km/hr = 72*5/18 =20m/s

t = 5min = 5*60 = 300

From the relation.

v = u+ at

20= 0 + a*300s

a = 20 /300

a = 1/15 = 0.0666666667

Distance travelled

s = ut + 1/2 at²

= 0. + 1/2 * 1/15 * (300)²

=0+ 1/2 * 1/15 * 90000

0+ 3000m

= 3000 m

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