Question

the velocity of a train is reduced uniformly from 40 km per second to 30 km per second while travelling a distance of 100 km calculate the retardation
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Answer 1

Answer:

3.5km/s^2

Step-by-step explanation:

Acceleration is constant, so the average velocity would be precisely 35km/s over a distance of 100km

Total time this trip would be 100/35=2.857 s

Changing velocity by negative 10 km/s over 2.857 seconds gives an acceleration of -3.5km/s^2

Answer 2

Answer:

3.5

Step-by-step explanation:

Given,

u=40km/hr

v=30km/hr

s=100km

According to 3rd eq of motion

v²-u²=2as

(30)²-(40)²= 2×a×100

900-1600=200a

-700=200a

-7=2a

-3.5=a

hence ratardation is 3.5km/hr²

........666........