/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 78 (a) Estimate the time it would t... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

(a) Estimate the time it would take to fill a private swimming pool with a capacity of 80,000 L using a garden hose delivering 60 L/min. (b) How long would it take if you could divert a moderate size river, flowing at \(5000 \mathrm{m}^{3} / \mathrm{s}\) into the pool?

Short Answer

Expert verified
(a) It would take approximately 22.22 hours to fill the swimming pool using a garden hose delivering 60 L/min. (b) It would take 0.016 seconds to fill the swimming pool by diverting a moderate size river flowing at \(5000 \mathrm{m}^{3} / \mathrm{s}\).

Step by step solution

01

Understand the problem

Read the problem carefully to understand that the capacity of the swimming pool is 80,000 L, and we have to calculate the time it would take to fill it up using two different methods.
02

Convert capacity to a uniform unit

In part (a), the garden hose delivers water at a rate of 60 L/min, and in part (b), the river flows at a rate of \(5000 \mathrm{m}^{3} / \mathrm{s}\). To proceed with the calculation, first, we need to convert the capacity of the swimming pool to a uniform unit. In this case, we will convert the capacity from liters to cubic meters. For that, use the following conversion: 1 L = 0.001 m³. So, \(80,000 \times 0.001 = 80 \mathrm{m}^{3}\).
03

Calculate time to fill the pool using a garden hose

Now, we have the capacity of the pool in cubic meters (80 m³), and the flow rate of the garden hose in liters per minute (60 L/min). First, let's convert the flow rate of the hose to cubic meters per minute. Use the same conversion: 1 L = 0.001 m³. So, \(60 \times 0.001 = 0.06 \mathrm{m}^{3}\)/min. Next, to calculate the time, divide the pool capacity by the flow rate of the garden hose: Time_to_fill = Pool_capacity / Flow_rate_of_garden_hose Substitute the values: Time_to_fill = \(80 \mathrm{m}^{3} / 0.06 \mathrm{m}^{3}\)/min Calculate the time: Time_to_fill = 1333.33 min Finally, convert minutes to hours: Time_to_fill = \(\frac{1333.33 \mathrm{min}}{60} = 22.22 \mathrm{hours}\) (approximately)
04

Calculate time to fill the pool using a river flow

In part (b), the river flows at a rate of \(5000 \mathrm{m}^{3} / \mathrm{s}\). To calculate the time, divide the pool capacity by the flow rate of the river: Time_to_fill = Pool_capacity / Flow_rate_of_river Substitute the values: Time_to_fill = \(80 \mathrm{m}^{3} / 5000 \mathrm{m}^{3}\)/s Calculate the time: Time_to_fill = 0.016 s
05

Present the final answer

(a) It would take approximately 22.22 hours to fill the swimming pool using a garden hose delivering 60 L/min. (b) It would take 0.016 seconds to fill the swimming pool by diverting a moderate size river flowing at \(5000 \mathrm{m}^{3} / \mathrm{s}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Volume Conversion
Understanding volume conversion is crucial when dealing with measurements in varying units. In our example, the pool's volume is given in liters, but the flow rate of the river is in cubic meters per second. To make accurate calculations, we need these measurements in the same unit.

Volume conversion follows a simple but essential principle: the conversion factor. For instance, to convert liters to cubic meters, the conversion factor is 0.001 cubic meters per liter, because there are 1,000 liters in one cubic meter. By multiplying the volume in liters by the conversion factor, you obtain the volume in cubic meters. This step allows for direct comparison and computation, which is vital for evaluations like determining how long it would take to fill a pool.
Rate of Flow
The rate of flow, often measured in volume per unit of time, tells us how quickly a fluid moves through a given cross-section. In fluid dynamics, this is a fundamental concept because it helps understand how fast systems like pipes or rivers can deliver water.

Calculating the rate of flow is straightforward: divide the volume by the time it took for that volume to flow. In our example with the garden hose and river, the flow rates are given, but when only the total volume and time are known, the rate of flow can be calculated by inverting the operation used to find time.

Understanding flow rates is essential in fields ranging from engineering to environmental science, as they directly affect how systems are designed and how they operate. In a practical scenario, like filling our hypothetical swimming pool, it demonstrates the vast difference in time required when using a garden hose versus a river, illustrating the power of flow rates in real-world applications.
Unit Conversion
Unit conversion is a necessary skill in many scientific and engineering fields. Any time you are presented with quantities in different units, as in the swimming pool problem, unit conversion ensures that you can compare 'apples to apples.' To convert units, use a conversion factor that relates the two units, like converting from minutes to seconds or liters to cubic meters.

Within the SI unit system, multiples and submultiples are often in powers of ten, making conversion relatively straightforward. However, when converting between SI and non-SI units or between units within either system that aren't simply related by powers of ten, it's crucial to know or look up the correct conversion factor.

Incorrect unit conversion can lead to a miscalculation which in practical situations can cause significant mistakes or inefficiencies, hence why accuracy and attention to detail are paramount. For students, mastering unit conversion is not only about finding the right answers but also about developing a rigorous approach to problem-solving.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Verify that work input equals work output for a hydraulic system assuming no losses due to friction. Do this by showing that the distance the output force moves is reduced by the same factor that the output force is increased. Assume the volume of the fluid is constant. What effect would friction within the fluid and between components in the system have on the output force? How would this depend on whether or not the fluid is moving?

Do fluids exert buoyant forces in a "weightless" environment, such as in the space shuttle? Explain your answer.

A certain hydraulic system is designed to exert a force 100 times as large as the one put into it. (a) What must be the ratio of the area of the cylinder that is being controlled to the area of the master cylinder? (b) What must be the ratio of their diameters? (c) By what factor is the distance through which the output force moves reduced relative to the distance through which the input force moves? Assume no losses due to friction.

A man has a mass of \(80 \mathrm{kg}\) and a density of \(955 \mathrm{kg} / \mathrm{m}^{3}\) (excluding the air in his lungs). (a) Calculate his volume. (b) Find the buoyant force air exerts on him. (c) What is the ratio of the buoyant force to his weight?

A garden hose with a diameter of \(2.0 \mathrm{cm}\) is used to fill a bucket, which has a volume of 0.10 cubic meters. It takes 1.2 minutes to fill. An adjustable nozzle is attached to the hose to decrease the diameter of the opening, which increases the speed of the water. The hose is held level to the ground at a height of 1.0 meters and the diameter is decreased until a flower bed 3.0 meters away is reached. (a) What is the volume flow rate of the water through the nozzle when the diameter is \(2.0 \mathrm{cm}\) ? (b) What is the speed of the water coming out of the hose? (c) What does the speed of the water coming out of the hose need to be to reach the flower bed 3.0 meters away? (d) What is the diameter of the nozzle needed to reach the flower bed?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.