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A city planner is working on the redesign of a hilly portion of a city. An important
Chapter 4, Problem 74GP(choose chapter or problem)
Problem 74GP
A city planner is working on the redesign of a hilly portion of a city. An important consideration is how steep the roads can be so that even low-powered cars can get up the hills without slowing down. A particular small car, with a mass of 1100 kg, can accelerate on a level road from rest to 21 m/s (75 km/h) in 14.0 s. Using these data, calculate the maximum steepness of a hill.
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QUESTION:
Problem 74GP
A city planner is working on the redesign of a hilly portion of a city. An important consideration is how steep the roads can be so that even low-powered cars can get up the hills without slowing down. A particular small car, with a mass of 1100 kg, can accelerate on a level road from rest to 21 m/s (75 km/h) in 14.0 s. Using these data, calculate the maximum steepness of a hill.
ANSWER:
Solution 74 GP
Step 1az:
We are going to find the steepness of a road to be redesigned for the small cars without slowing down. The car starts from the rest to the final v in t seconds.
The mass of the car m = 1100 kg
The initial speed vo = 0
The final speed v = 21 m/s
The acceleration due to gravity g = 9.8 m/s2
The time taken to reach v (t) = 14 s