This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Why is an umbrella in danger of being turned inside out on a windy day? What will be an ideal ... (Read 128 times)

Mr.Thesaxman

  • Hero Member
  • *****
  • Posts: 514
on: Jul 29, 2018
Why is an umbrella in danger of being turned inside out on a windy day?
 
  What will be an ideal response?

Question 2

Which is greater, the buoyant force that acts on an elephant, or on a helium-filled party balloon? Explain why the balloon rises in air and the elephant doesn't.
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

dreamfighter72

  • Sr. Member
  • ****
  • Posts: 355
Reply #1 on: Jul 29, 2018
Answer to Question 1

Answer: Because of the umbrella's curvature, air passes faster over its top than across its bottom. This produces a difference in forces, and like an airplane wing, experiences lift. This is in accord with Bernoulli's principle. The lift can turn or flip the umbrella inside out.

Answer to Question 2

Answer: The buoyant force exerted by the atmosphere on any body is equal to the weight of air displaced. Since an elephant has more volume, it displaces more air and has a greater buoyant force on it than the buoyant force on the smaller helium-filled balloon. Whether or not something rises has to do with the relative magnitudes of the buoyant force and the force due to gravity. Aha, the force of gravity on the elephant is enormously greater than the buoyant force on the elephant. So gravity wins and the elephant is pressed to the surface. But for the balloon, its weight is less than the small buoyant force it experiences. Buoyant force wins and the balloon rises.


Mr.Thesaxman

  • Member
  • Posts: 514
Reply 2 on: Jul 29, 2018
YES! Correct, THANKS for helping me on my review

coreycathey

  • Member
  • Posts: 333
Reply 3 on: Yesterday
Wow, this really help

« previous next »
 

Did you know?

Your heart beats over 36 million times a year.

Did you know?

The average adult has about 21 square feet of skin.

Did you know?

As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.

Did you know?

A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.

Did you know?

For high blood pressure (hypertension), a new class of drug, called a vasopeptidase blocker (inhibitor), has been developed. It decreases blood pressure by simultaneously dilating the peripheral arteries and increasing the body's loss of salt.

stereocilia inside the ear stereocilia inside the ear
A farmer with a pitchfork, wearing a hat identifying him as a Granger, warns of an oncoming “Consoli A farmer with a pitchfork, wearing a hat identifying him as a Granger, warns of an oncoming “Consoli
The Number of Children Americans Think Are Ideal The Number of Children Americans Think Are Ideal
A track inside an ignition coil is not a short, but rather it is a low-resistance path or hole that ... A track inside an ignition coil is not a short, but rather it is a low-resistance path or hole that ...
Inside ankle press. Place the heel of your left hand on the ball of the recipient’s right foot, ... Inside ankle press. Place the heel of your left hand on the ball of the recipient’s right foot, ...
For the circuit in Figure 1, assume ideal diodes. The peak inverse voltage is approximately For the circuit in Figure 1, assume ideal diodes. The peak inverse voltage is approximately
Video: Summary of female reproductive cycle days 1-28

For a complete list of videos, visit our video library