Final answer:
Without the coefficient of friction or a specific formula, the speed of the car at the time of applying the brakes cannot be calculated accurately. For the second question, using a reference deceleration rate, we can approximate that Drake's car would cover about 200 feet before stopping, which does not match the given choices.
Step-by-step explanation:
To determine how fast the car was going when the driver applied the brakes, forensic techniques often employ formulas that relate the length of the skid mark to the speed of the vehicle. However, to provide an accurate answer, the coefficient of friction between the tires and the road and the deceleration rate must be known. Without this information or a specific formula, we cannot calculate the exact speed. As for Drake's situation, using a deceleration rate of 7 m/s² (from the provided reference), we can use the formula from physics to determine the stopping distance:
s = v² / (2 * a)
Where s is the stopping distance, v is the initial velocity (65 mph or about 29.1 m/s), and a is the deceleration. Converting 65 mph to meters per second, we get:
65 mph × 0.44704 = 29.06 m/s
Substituting the values, we obtain:
s = (29.06 m/s)² / (2 × 7 m/s²) = 29.06 × 29.06 / 14 = 60.54 m
Rounding to the nearest foot:
60.54 m × 3.28084 = 198.49 ft ≈ 200 feet
There do not seem to be any perfect matches with the answer choices; however, based on the calculation, the stopping distance would likely be over 125 feet.
Due to the lack of data (no coefficient of friction or a precise formula) for the first question and assuming a deceleration rate not given in the options for the second question, we cannot definitively select an answer from the multiple-choice options provided for either part of the student's questions.