Makakuha ng mga sagot sa iyong mga pinakamahahalagang tanong sa IDNStudy.com. Alamin ang mga maaasahang sagot sa iyong mga tanong mula sa aming malawak na kaalaman sa mga eksperto.

A vehicle takes 35 m to stop in an emergency from an initial speed of 63 km/h. One-fifth of the time elapses with the vehicle running at constant velocity before the driver reacts to the situation. Assuming constant deceleration when the brakes are applied, calculate (a) the reaction time, and (b) the distance covered during this time.
Given answer: a. 0.67 s and b. 12 m.

Solution needed


Sagot :

Answer:

6. A vehicle takes 35 m to stop in an emergency from an initial speed of 63 km/h. One-fifth of the time elapses with the vehicle running at constant velocity before the driver reacts to the situation. Assuming constant deceleration when the brakes are applied, calculate (a) the reaction time, and (b) the distance covered during this time.

Step 1: Given

Total distance traveled: s = 35 m

Initial speed: u = 63 km/h = 17.5 m/s

Final speed: v = 0 km/h = 0 m/s

One fifth of time elapses for reaction time: time of reaction: t1 = t5 time of reaction: t1 = t5  

Where, t is total time to stop the car

Four fifths of time is used to actual stoping mechanism: t2 = 4t5