I only need 3 questions answered in a short amount of time. questions 7-9 all you have to do is scroll down to read the instructions for 7-9 and show your work :)

Physical Science Group Report Spring20232022

Assignment Overview

BACKGROUND: Pro Stock drag racing involves cars lining up together in front of a light that turns green, and cars travel straight down a track (402 meters) to a finish line. Obviously the car that crosses with the smallest elapsed time wins. (To see a video of an example race: https://www.youtube.com/watch?v=ZtWadz3bNpE ). We will consider two major factors deciding who wins a pretend competition: the reaction time of the driver (the time between the driver seeing the green light and actually starting the car’s acceleration), and the value of the acceleration of the car, which we will assume is a constant positive acceleration until the car crosses the finish line. As you see from videos of drag races, parachutes are deployed immediately after a car crosses the finish line. We will assume that a constant negative “braking” acceleration caused by the parachute to slow the car down that is the SAME for each car, and determine the distance the car travels down the track area past the finish line until the car comes to a stop. (The length of track after the finish line used for this slowdown is called the “shutdown area” in racing lingo.)

Scenario you need to imagine for your group:

Each of you in your group is the driver of one of the following cars that competes in an imaginary drag race. Fill in the name of one group member next to each of the competing car pictures, as that will be the car the group member races in this imaginary competition. Assign the cars to your group members in alphabetical order, so that the group member who has a last name name, first alphabetically, gets the White Car below, and the last name alphabetically gets the Purple_car below. Also list here the overall average reaction time each group member shared from the Reaction Time Worksheet.

1) White_Car driver GROUP MEMBER NAME: _______________ REACTION TIME: ___0.489______

2) Orange_Car driver GROUP MEMBER NAME: _______________ REACTION TIME: _0.235___

3) Red_Car driver GROUP MEMBER NAME: _______________ REACTION TIME: _0.250___

4) Purple_Car driver GROUP MEMBER NAME: _______________ REACTION TIME: _________________

In this pretend competition, each car races down the track once, starting from an initial zero velocity, of course. The instant the green light appears to each driver, a timer clock starts to record their time. The total time for each drivers race has two parts: the reaction time (where the car is just sitting there until the driver actually puts the car into motion), and the time taken for the car to move the 402 m to the finish line while the car accelerates from rest to the maximum speed as it crosses the finish line (with the acceleration for the car given above.)

So the total time for each driver’s race is given by: ttot = tr + t ( tr is the reaction time and t is the time accelerating to the finish after the reaction time is over.) The distance (X-X0) is 402.0 meters (start to finish line).

5) USING THE APPROPRIATE EQUATIONS FROM CHAPTER 2 of our online text, fill out the following table that will include the total time for each race car, the final velocity as the race car crosses the finish line (both in units of m/s and mi/hr, (miles per hour). (Note: none of the appropriate Ch. 2 equations will make any use of the reaction time. The reaction time is just time added to the accelerating time, to get the total time including BEFORE the acceleration begins!) Since reaction time is part of the total time, the car with the biggest acceleration and largest final velocity may not win!

6) SHOW CLEARLY all the math steps, and the equations you used from Chapter 2 with the math steps, to get the values for accelerating time and final velocity values in the table above for each of the cars. SHOW YOUR WORK CLEARLY. ALSO list, according to the table results comparing the total times, which car came in 1st, 2nd, 3rd, and 4th place.

1st place:__________ 2nd:_________________ 3rd________________ 4th____________________

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Key = Distance(s), acceleration (a), initial velocity(u), reaction time(tr), accelerating time(t), total time(tot)

Accelerating time = distance formula s = ut + 1/2 at^2

Total time formula = tot = tr + t

Final velocity formula v = u + at

White car 402 = 0 + 1/2 (18.3)t^2 t = 12.006 /// orange car 402 = 0 + 1/2 (17.8)t^2 t= 12.173 /// red car 402 = 0 + 1/2

(18.1) t^2 t=12.072

tr + t = total time for all three cars

0.489 plus 12.006// 0.235 plus 12.173////// 0.250 plus 12.072////// equals total time

White car = 18.3 times 12.006 ///// 219.7098 m/s ///// 491.47682 mi/h

Orange car = 17.8 times 12.173//// 216.6794 m/s ///// 484.698013 mi/h

Red car = 18.1 times 12.072 ///// 218.5032 m/s /

//| 488.777738 mi/h

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For the last part of this report, we will concentrate on the motion of each car from the moment it crosses the finish line, when the braking starts to occur due to the parachute, until the car comes to a complete stop.

Assume each car has the same negative “braking acceleration” of -14.2 m/s2 during this motion.

The initial velocity for this part of the motion will be the (positive) velocity (v) in m/s you found in the table above, and the final velocity for this part of the motion will be 0 m/s, as the car comes to a complete stop.

For each car above, find the distance the car moves (X - X0) while undergoing this braking acceleration until it comes to a stop, in units of both meters and feet. This will be the distance from the finish line to the final resting place of the car.

Show your work CLEARLY, showing how you use an equation or equations from Chapter 2 to find the distances.

7: Distance White_car moves until coming to a stop: ______________ meters _______________feet

SHOW WORK/CALCULATIONS:

8: Distance Orange_car moves until coming to a stop: ______________ meters _______________feet

SHOW WORK/CALCULATIONS

9: Distance Red_car moves until coming to a stop: ______________ meters _______________feet

SHOW WORK/CALCULATIONS

10: Distance Purple_car moves until coming to a stop: ___none_______ meters _______none______feet

SHOW WORK/CALCULATIONS