The driver of a car travelling at 72 kmph observes the light 300 m ahead of him turning red.The traffic light is timed to remain red for 20 s before it turns green . If the motorist wisher to pass the light without stopping to wait for it t turn green , determine.The speed with which the motorist crosses the traffic light .

The driver of a car travelling at 72 kmph observes the light 300 m ahe

1.	The driver of a car travelling at 72 kmph observes the light 300 m ahead of him turning red.The traffic light is timed to remain red for 20 s before it turns green . If the motorist wisher to pass the light without stopping to wait for it t turn green , determine.The speed with which the motorist crosses the traffic light .
Answer» SOLUTION :Given u = 72 KMPH`= 72 xx (5)/(18) ms^(-1)` `= 20 ms^(-1) , s = 300 m, t = 20s, a = ?, v = ?` `v = u + at = 20 - 0 . 5 xx 20` `= 10 ms^(-1)`