9. Laura walks every evening on the edges of a sports field near her house. The field is in the shape of a rectangle 300 feet (ft) long and 200 ft wide, so 1 lap on the edges of the field is 1,000 ft. She enters through a gate at point G, located exactly halfway along the length of the field. Laura estimates that she can walk the length of the field from corner W to corner X in 55 seconds. To the nearest tenth of a mile per hour, what is her walking speed? (1 mile = 5,280 feet)
Answer: B
Laura's walking speed is 5.5 miles per hour.
To calculate Laura's walking speed, we first determine the distance she walks in one lap around the field, which is 1,000 feet. Since she takes 55 seconds to walk the length of the field (300 feet), we can find her speed in feet per second and then convert it to miles per hour.
A) 3.7
Option A is incorrect because it underestimates Laura's walking speed. The calculations show that her speed is higher than 3.7 miles per hour, given the time taken to walk the length of the field.
B) 5.5
Option B is correct. Laura walks 300 feet in 55 seconds, which translates to a speed of approximately 5.5 miles per hour when converted from feet per second to miles per hour. This accurately reflects her walking speed based on the distance covered in the given time.
C) 3.4
Option C is incorrect as it is also lower than the calculated walking speed. The time taken to walk 300 feet indicates that Laura's pace is faster than 3.4 miles per hour, making this option unviable.
D) 5.3
Option D is incorrect because it slightly underestimates Laura's walking speed. The conversion from her walking time indicates her speed is closer to 5.5 miles per hour than 5.3, hence making this choice inaccurate.
Conclusion
In conclusion, the correct answer is B) 5.5 miles per hour, as it accurately reflects Laura's calculated walking speed based on the time and distance provided. All other options fall short of this correct calculation, demonstrating their inaccuracy in relation to the context of the problem.