How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask David Your Own Question

David
David, Tutor
Category: Homework
Satisfied Customers: 2310
Experience:  PhD in Theoretical Physics
394177
Type Your Homework Question Here...
David is online now
A new question is answered every 9 seconds

An airplane is flying with a velocity of 240 m/s at an angle

Customer Question

An airplane is flying with a velocity of 240 m/s at an angle of 30 degrees with the horizontal (in a downward dive). When the altitude of the plane is 2.4 KM a flare is released from the plane. The flare hits the target on the ground. What is the angle theta (angle between line of sight and ground)
Submitted: 2 years ago.
Category: Homework
Expert:  David replied 2 years ago.

David :

hello

David :

here is the solution

David :


we have the initial velocity of the flare is 240 m/s at 30 deg below horizontal
First we calculate the time it takes to reach the ground:
h=vo*t*sin(30)+0.5gt^2
2400 = 240*t*0.5+4.9t^2
2400 = 120*t+4.9t^2
positive solution of this quadratic equation is t=13.05 sec
the negative solution is not physical.
now calculate the vertical speed of the flare just before it hits the ground
Vy = Vosin(30)+gt = 120+9.8*13.05 = 247.89
and horizontal velocity is
Vx= Vocos(30)=207.85
so the angle we are looking for is:
theta = atan(Vy/Vx) = atan(247.89/207.85)=50 degrees

David :

Answer: 50 degrees below horizontal

David :

hope this helps

David, Tutor
Category: Homework
Satisfied Customers: 2310
Experience: PhD in Theoretical Physics
David and 12 other Homework Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Last | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Manal Elkhoshkhany

    Tutor

    Satisfied Customers:

    4520
    More than 5000 online tutoring sessions.
< Last | Next >
  • http://ww2.justanswer.com/uploads/BU/BusinessTutor/2012-2-2_115741_Kouki2.64x64.jpg Manal Elkhoshkhany's Avatar

    Manal Elkhoshkhany

    Tutor

    Satisfied Customers:

    4520
    More than 5000 online tutoring sessions.
  • http://ww2.justanswer.com/uploads/LI/lindaus/2012-6-10_04811_IMG20120609164157.64x64.jpg Linda_us's Avatar

    Linda_us

    Finance, Accounts & Homework Tutor

    Satisfied Customers:

    3121
    Post Graduate Diploma in Management (MBA)
  • http://ww2.justanswer.com/uploads/ComputersGuru/2010-02-13_051118_Photo41.JPG LogicPro's Avatar

    LogicPro

    Engineer

    Satisfied Customers:

    3035
    Expert in Java C++ C C# VB Javascript Design SQL HTML
  • http://ww2.justanswer.com/uploads/lanis/2009-4-1_233717_phput9xef_c1pm.jpg Lani S.'s Avatar

    Lani S.

    Tutor

    Satisfied Customers:

    2457
    Registered Nurse, Internet Researcher, Private Tutor
  • http://ww2.justanswer.com/uploads/chooser77/2009-08-18_162025_Chris.jpg Chris M.'s Avatar

    Chris M.

    M.S.W. Social Work

    Satisfied Customers:

    2341
    Master's Degree, strong math and writing skills, experience in one-on-one tutoring (college English)
  • http://ww2.justanswer.com/uploads/JawaadAhmed/2009-6-27_12137_SIs_SHadi.jpg F. Naz's Avatar

    F. Naz

    Chartered Accountant

    Satisfied Customers:

    1975
    Experience with chartered accountancy
  • http://ww2.justanswer.com/uploads/JK/jkcpa/2011-1-16_182614_jkcpa.64x64.jpg Bizhelp's Avatar

    Bizhelp

    CPA

    Satisfied Customers:

    1873
    Bachelors Degree and CPA with Accounting work experience