yrtherenonames
Member
- Joined
- Mar 26, 2004
- Messages
- 154
- Gender
- Male
- HSC
- 2005
Well, half yearly's coming up on Monday and everything's just about sorted except this past question from the '99 HSC; I should be able to figure it out, but my head hurts, and the BoS explanation just confuses me. It's question 6b) for those of you playing at home. Anyway so resisted motion:
A ball of unit mass is projected vertically upwards from ground level with initial speed U. Assume that air resistance is kv, where v is the ball's speed, k a positive constant.
Consider the ball's motion as it falls back to ground level. Let y be the displacement of the ball measure vertically downwards from the point of maximum height, t be the time elapsed after the ball has reached maximum heigh and g be acceleration due to gravity.
From here they get you to prove all these lovely little formulae, including
t=(v+ky)/g, now onto my question.
(v)You are given that the ball reaches a maximum height...which is so messy it's not worth writing out, just check out the hyperlink below.
Deduce that the total time T that the ball is in the air is T=(U+V)/g, where V is the final speed that the ball reaches when returning to ground level.
If that was all too messy for you, you can read it here.
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2000exams/hsc00_maths/99MATH4U.PDF
Thanks in advance
A ball of unit mass is projected vertically upwards from ground level with initial speed U. Assume that air resistance is kv, where v is the ball's speed, k a positive constant.
Consider the ball's motion as it falls back to ground level. Let y be the displacement of the ball measure vertically downwards from the point of maximum height, t be the time elapsed after the ball has reached maximum heigh and g be acceleration due to gravity.
From here they get you to prove all these lovely little formulae, including
t=(v+ky)/g, now onto my question.
(v)You are given that the ball reaches a maximum height...which is so messy it's not worth writing out, just check out the hyperlink below.
Deduce that the total time T that the ball is in the air is T=(U+V)/g, where V is the final speed that the ball reaches when returning to ground level.
If that was all too messy for you, you can read it here.
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2000exams/hsc00_maths/99MATH4U.PDF
Thanks in advance
