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Motion In A Plane

Question
CBSEENPH11020433

A car starting from rest accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then

  • S=ft

  • S= ft2/72

  • S = 1/2 ft2

  • S = 1/4 ft2

Solution

B.

S= ft2/72


straight S space equals space fraction numerator ft subscript 1 superscript 2 over denominator 2 end fraction
straight v subscript straight o space equals square root of 2 Sf end root
During space retardation
straight S subscript 2 space equals space 2 straight S
During space constant space velocity
15 straight S space minus 3 straight S space equals space 12 space straight S space equals straight v subscript straight o straight t
rightwards double arrow space straight S space equals ft squared over 72