This topic contains a solution. Click here to go to the answer

Author Question: A force of 5.3 N is needed to hold on to an umbrella in a strong wind. If the air molecules each ... (Read 33 times)

formula1

  • Hero Member
  • *****
  • Posts: 666
A force of 5.3 N is needed to hold on to an umbrella in a strong wind. If the air molecules each have a mass of 4.7 10-26 kg,
 
  and each one strikes the umbrella (without rebounding) with a speed of 2.0 m/s in the same direction, how many molecules strike the umbrella each second? Assume that the wind blows horizontally so that the gravitational force exerted on the air molecules can be neglected.

Question 2

A spherical ball of lead (density 11.3 g/cm3 ) is placed in a tub of mercury (density 13.6 g/cm3 ). Which answer best describes the result?
 
  A) The lead ball will float with about 17 of its volume above the surface of the mercury.
  B) The lead ball will float with about 83 of its volume above the surface of the mercury.
  C) The lead will sink to the bottom of the mercury.
  D) The lead ball will float with its top exactly even with the surface of the mercury.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

mjenn52

  • Sr. Member
  • ****
  • Posts: 351
Answer to Question 1

5.6 1025 per second

Answer to Question 2

A




formula1

  • Member
  • Posts: 666
Reply 2 on: Jul 29, 2018
:D TYSM


fatboyy09

  • Member
  • Posts: 358
Reply 3 on: Yesterday
Excellent

 

Did you know?

People about to have surgery must tell their health care providers about all supplements they take.

Did you know?

It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.

Did you know?

Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

Did you know?

Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.

Did you know?

Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).

For a complete list of videos, visit our video library