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A car is moving with speed 20 m//s. Sudd...

A car is moving with speed `20 m//s`. Suddenly the driver sees the sign of danger at a distance of `50 m`, after a certain reaction time `t_(0)`, he applies breaks to cause deceleration `5 m//s^(2)`. What is the maximum allowable reaction time `t_(0)` to avoid accident and distance traveled by the car during reaction time?

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`v^(2)=u^(2)-2as`
`0=(20)^(2)-2xx5d_(2) implies d_(2)=40 m`
`d_(1)+d_(2)=50`
`20 t_(0)+40=50 implies t_(0)=0.55 s`
`d_(1)=20 t_(0)=10 m`
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CP SINGH-MOTION IN A STRAIGHT LINE-EXERCISES
  1. A car is moving with speed 20 m//s. Suddenly the driver sees the sign ...

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  2. The ratio of the numerical values of the average velocity and average ...

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  3. Which of the following is a one-dimensional motion ?

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  4. A point traversed half a circle of radius r during a time interval t(0...

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  5. A particle moves 3 m north, then 4 m east, and then 12 m vertically up...

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  6. A person travelling on a straight line moves with a uniform velocity v...

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  7. A car moves from X to Y with a uniform speed vu and returns to Y with ...

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  8. A particle moves in a straight line from A to B (a) for the first ha...

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  9. If a car covers (2)/(5)^(th) of the total distance with v1 speed and (...

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  10. A car travels half the distance with a constant velocity of 40 m//s an...

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  11. One car moving on a staright road covers one-third of the distance wit...

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  12. A particle moving in a straight line covers half the distance with spe...

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  13. A body starts from rest. What is the retio of the distance traveled by...

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  14. A partical is moving in a straight line under constant acceletation. I...

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  15. A particle is moving in a straight line under constant acceleration of...

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  16. A body is moving with a uniform acceleration coverss 40 m in the first...

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  17. A particle starts its motion from rest under the action of a constant ...

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  18. A body travels for 15 s starting from rest with a constant acceleratio...

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  19. A body moving with a uniform acceleration crosses a distance of 15 m i...

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  20. A 150 m long train is moving with a uniform velocity of 45 km//h. The ...

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  21. Speeds of two identical cars are u and 4u at at specific instant. The ...

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