- #1
parm12
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The driver of a car wishes to pass a truck that is traveling at a constant speed of 19.0 m/s. Initially, the car is also traveling at a speed 19.0 m/s and its front bumper is a distance 23.7 m behind the truck's rear bumper. The car begins accelerating at a constant acceleration 0.550 m/s^2, then pulls back into the truck's lane when the rear of the car is a distance 25.4 m ahead of the front of the truck. The car is of length 4.90 m and the truck is of length 21.8 m. How much time is required for the car to pass the truck?
I'm having trouble understanding why 13.5 s is incorrect.
Here is my approach:
T_position = 19(m/s)t + 50.4m (50.4 = Car length + Truck Length + Distance in beteen)
C_position = .275(m/s^2)t^2 + 19(m/s)t
C_position corresponds to the rear of the car, and T_position the front of the truck.
Solving for both position equations yields:
50.4m = .275(m/s^2)t^2
sqrt(50.4/.275) = t = 13.5s
I'm having trouble understanding why 13.5 s is incorrect.
Here is my approach:
T_position = 19(m/s)t + 50.4m (50.4 = Car length + Truck Length + Distance in beteen)
C_position = .275(m/s^2)t^2 + 19(m/s)t
C_position corresponds to the rear of the car, and T_position the front of the truck.
Solving for both position equations yields:
50.4m = .275(m/s^2)t^2
sqrt(50.4/.275) = t = 13.5s