Jack is traveling South at a steady 60.0 mi/hr (26.8 m/s) on a straight portion of Route 3. The car directly ahead of hi
Posted: Thu Apr 28, 2022 9:41 am
Jack is traveling South at a steady 60.0 mi/hr (26.8 m/s) on a
straight portion of Route 3. The car directly ahead of him is also
traveling at 60 mi/hr. Jack is keeping what he feels is a safe
distance from the car directly ahead of him, 25.0 m (roughly 5.6
car lengths). Suddenly at t = 0, having noticed a posted speed
limit of 30.0 mi/hr (due to road construction), the driver of the
car ahead slams on his brakes and begins to slow down at a steady
rate of 10.0m/s^2. Once he has slowed down to 30.0 mi/hr (13.4
m/s), he plans to maintain this constant speed. Suppose that it
takes Jack 1.00 second to notice that the car ahead has slowed
down, and another 2.00 seconds to effectively apply his brakes.
Also suppose that, once he has applied his brakes, Jack’s car slows
down at a steady rate of 10.0m/s^2.
16. Assume, for the sake of argument, that no collision occurs.
What distance will Jack’s car travel while he is in the process of
slowing down to 30.0 mi/hr?
A. 25.0 m. B. 53.9 m. C. 78.9 m. D. 26.9 m. E. 135 m.
17. Which of the following statements is true?
A. A collision occurs before the car ahead has slowed down to
30.0 mi/hr?
B. A collision occurs after the car ahead has slowed down to
30.0 mi/hr but before Jack has even applied his brakes?
C. A collision occurs after Jack has applied his brakes but
before he can slow down to 30.0 mi/hr?
D. There is no collision, but at the instant Jack’s car has
slowed down to 30.0 mi/hr, his front bumper is less than 3.00
meters from the rear bumper of the car ahead.
E. There is no collision, but at the instant Jack’s car has
slowed down to 30.0 mi/hr, his front bumper is less than 1.00 meter
from the rear bumper of the car ahead.
straight portion of Route 3. The car directly ahead of him is also
traveling at 60 mi/hr. Jack is keeping what he feels is a safe
distance from the car directly ahead of him, 25.0 m (roughly 5.6
car lengths). Suddenly at t = 0, having noticed a posted speed
limit of 30.0 mi/hr (due to road construction), the driver of the
car ahead slams on his brakes and begins to slow down at a steady
rate of 10.0m/s^2. Once he has slowed down to 30.0 mi/hr (13.4
m/s), he plans to maintain this constant speed. Suppose that it
takes Jack 1.00 second to notice that the car ahead has slowed
down, and another 2.00 seconds to effectively apply his brakes.
Also suppose that, once he has applied his brakes, Jack’s car slows
down at a steady rate of 10.0m/s^2.
16. Assume, for the sake of argument, that no collision occurs.
What distance will Jack’s car travel while he is in the process of
slowing down to 30.0 mi/hr?
A. 25.0 m. B. 53.9 m. C. 78.9 m. D. 26.9 m. E. 135 m.
17. Which of the following statements is true?
A. A collision occurs before the car ahead has slowed down to
30.0 mi/hr?
B. A collision occurs after the car ahead has slowed down to
30.0 mi/hr but before Jack has even applied his brakes?
C. A collision occurs after Jack has applied his brakes but
before he can slow down to 30.0 mi/hr?
D. There is no collision, but at the instant Jack’s car has
slowed down to 30.0 mi/hr, his front bumper is less than 3.00
meters from the rear bumper of the car ahead.
E. There is no collision, but at the instant Jack’s car has
slowed down to 30.0 mi/hr, his front bumper is less than 1.00 meter
from the rear bumper of the car ahead.