Using your Texting and Driving Spreadsheet: Velocity of the Car: 10 m/s Time of distraction: 8.0 sec Time of reaction: 0.5 sec Velocity after braking: 0.0 m/s Deceleration due to braking: -8.0 m/s/s Warm Up If roads were icy: 1. What would you change in the inputs above and why? Now, what is: 2. Distance while distracted: m 3. Distance while reacting: m 4. Time while braking: sec 5. Distance while braking: m 6. Total distance: m

1. I would like to change the time of distraction. Because 8 s is a long time to be distracted while driving on the road. Its not safe for the driver and the other people on road if the driver is distracted even for a second.

2. s₁ = 80 m

3. s₂ = 5 m

4. t = 1.25 s

5. s₃ = 7.5 m

6. s = 92.5 m    

Explanation:

1.

I would like to change the time of distraction. Because 8 s is a long time to be distracted while driving on the road. Its not safe for the driver and the other people on road if the driver is distracted even for a second.

2.

Distance Covered While Distracted = s₁ = (speed of car)(distraction time)

s₁ = (10 m/s)(8 s)

s₁ = 80 m

3.

Distance Covered While Reacting = s₂ = (speed of car)(reaction time)

s₂ = (10 m/s)(0.5 s)

s₂ = 5 m

4.

Using 1st equation of motion braking motion:

Vf = Vi + at

where,

Vf = Final Speed = 0 m/s

Vi = Initial Speed = 10 m/s

a = acceleration = - 8m/s²

t = ?

Therefore,

0 m/s = 10 m/s + (-8m/s²)t

t = (10 m/s)/(8 m/s²)

t = 1.25 s

5.

Now, using second equation of motion:

Distance Covered While Braking = s₃ = Vi t + (1/2)at²

s₃ = (10 m/s)(1.25 s) + (1/2)(-8m/s²)(1.25 s)²

s₃ = 12.5 m - 5 m

s₃ = 7.5 m

6.

Total Distance = s = s₁ + s₂ + s₃

s = 80 m + 5m + 7.5 m

s = 92.5 m