« previous next »

Author Question: On sunny days, why do hot-air balloons suddenly rise when they drift over a wide road or a black ... (Read 92 times)

debasdf

  • Hero Member
  • *****
  • Posts: 570
on: Jul 29, 2018
On sunny days, why do hot-air balloons suddenly rise when they drift over a wide road or a black asphalt parking lot?
 
  What will be an ideal response?

Question 2

In one word, account for water temperature exceeding 100C in the power plant of a nuclear submarine.
 
  A) conductivity
  B) evaporation
  C) condensation
  D) pressure
  E) vaporization


amandanbreshears

  • Sr. Member
  • ****
  • Posts: 320
Reply #1 on: Jul 29, 2018
Answer to Question 1

Answer: Air over a warm surface is warmed, becomes less dense, and is buoyed upward. That is why air warmed by a hot black surface rises. Hence a balloon is carried upward by the rising air.

Answer to Question 2

Answer: D


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Dogs have been used in studies to detect various cancers in human subjects. They have been trained to sniff breath samples from humans that were collected by having them breathe into special tubes. These people included 55 lung cancer patients, 31 breast cancer patients, and 83 cancer-free patients. The dogs detected 54 of the 55 lung cancer patients as having cancer, detected 28 of the 31 breast cancer patients, and gave only three false-positive results (detecting cancer in people who didn't have it).

Did you know?

In 1885, the Lloyd Manufacturing Company of Albany, New York, promoted and sold "Cocaine Toothache Drops" at 15 cents per bottle! In 1914, the Harrison Narcotic Act brought the sale and distribution of this drug under federal control.

Did you know?

Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.

Did you know?

Approximately one in four people diagnosed with diabetes will develop foot problems. Of these, about one-third will require lower extremity amputation.

Did you know?

Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.

A Black cat under the snow. A Black cat under the snow.
Supermassive Black Hole Supermassive Black Hole
Jets Created by a Black Hole in a Binary System Jets Created by a Black Hole in a Binary System
Wegener’s Evidence for Continental Drift Wegener’s Evidence for Continental Drift
Creed - With Arms Wide Open Creed - With Arms Wide Open
Using a black light to spot leaks after adding dye to the oil. Using a black light to spot leaks after adding dye to the oil.
Video: Tuberculosis Testing

For a complete list of videos, visit our video library