Ms. Terry Novel is driving down the highway at 26 m/s when the driver sees the light ahead turn yellow. It takes the driver 0.3 s to react and the maximum braking acceleration of her car is 5.3 m/s2. If the light stays yellow for a total of 4 seconds, how far does she travel in this time?

Question

Physics

Samir Jones

6 January, 19:45

Ms. Terry Novel is driving down the highway at 26 m/s when the driver sees the light ahead turn yellow. It takes the driver 0.3 s to react and the maximum braking acceleration of her car is 5.3 m/s2. If the light stays yellow for a total of 4 seconds, how far does she travel in this time?

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Answers (1)

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Rogelio Crawford · Answer 1

67.8 m.

Explanation:

For 0.3 sec which is the response time, he will keep on moving with velocity

undiminished or at 26 m/s.

Distance travelled during this period

= 26 x. 3 = 7.8 m

For rest of the time ie during 4 -.3 = 3.7 s, he decelerates with deceleration of 5.3 ms⁻² and initial velocity of 26 m/s

s = u t - 1/2 a t²

s = 26 x 3.7 -.5 x 5.3 x 3.7 x 3.7

= 96.2 - 36.28

= 60 m approx.

Total distance travelled

=60 + 7.8 = 67.8 m.