Ranking three football paths by flight time, horizontal velocity and initial speed

[mmattson07]

Homework Statement

In the following questions, you will be ranking these paths a) time of flight b) initial horizontal velocity component and c)initial speed.

If multiple paths rank equally, use the same rank for each, then exclude the intermediate ranking (i.e. if objects A, B, and C must be ranked, and A and B must both be ranked first, the ranking would be A:1, B:1, C:3). If all paths rank equally, rank each as '1'.
Figure 4-26 shows three paths for a football kicked from ground level.

Homework Equations

FIGURE 4-26

http://edugen.wiley.com/edugen/courses/crs4957/art/qb/qu/c04/image_eprof69118_c04q_cq_1_9_eat_11831454619810_6638757528936116.jpg

The Attempt at a Solution

Time of flight: a) 1 b) 2 c)3
Initial horizontal velocity component: a) 1 b)1 c)1
Initial speed: a)1 b)2 c)3

Just want to make sure I understand this correctly. Thanks!

 

[rl.bhat]

Where is the figure?

 

[mmattson07]

It should be there under Relevant Equations. I see it fine?

 

[rl.bhat]

Since maximum heights of the projectiles are the same, the time of flights must be the same. Other things are correct.

 

[mmattson07]

Okay. I thought that might be the case but since their initial vertical velocities are different I thought that might affect flight time.

 

[rl.bhat]

Okay. I thought that might be the case but since their initial vertical velocities are different I thought that might affect flight time.

Initial vertical velocities are different but v*sinθ is constant and h is also constant. So t is constant.

 

[Olly4]

I'm not sure, but the figures seem a little off. By which I mean they don't seem perfect parabolas, but a little stunted, like when a friction component is induced. Does the question say whether friction or not?

 

[mmattson07]

The problem indicates to ignore the effects of air.

 

[Olly4]

Ok then you should be fine