• Support PF! Buy your school textbooks, materials and every day products Here!

Odd projectile motion question.

  • #1

Homework Statement


Question: "The time of flight of the lure through the air is 3.4 seconds. (g= 9.8m/s/s)
Calculate the maximum height of the lure in its projectile motion."


Homework Equations


Not sure if I need to use this:
d = (u)(t) + (1/2)(a)(t^2)


The Attempt at a Solution



I don't know how this really works...

I'm guess to half the time (3.4/2). Thats the time when the object is at rest for a very short time (initial velocity would be 0). And use that equation on to solve the d.
 

Answers and Replies

  • #2
Borek
Mentor
28,296
2,680
Once the object is at rest (top of the trajectory) what follows (on the vertical axis) is just a free fall, isn't it?
 
  • #3
CAF123
Gold Member
2,889
88
You could start by finding the initial vertical component of velocity and using another kinematic relation to find the height. Or do as Borek suggested.
 
  • #4
So...

d = (0)(1.6) + (1/2)(9.8)(1.6)^2

= 12.544 m

Is it right?
 
  • #5
1,065
10
The time of flight of the lure through the air is 3.4 seconds means the lure left the earth at t=0 and landed back to earth at 3.4sec.

So vertically the final position is back to where it started.
Y position is a horizontal line parallel to x-axis.
 
  • #6
Doc Al
Mentor
44,862
1,109
So...

d = (0)(1.6) + (1/2)(9.8)(1.6)^2

= 12.544 m

Is it right?
Right idea, but 3.4/2 ≠ 1.6. :wink:
 

Related Threads for: Odd projectile motion question.

  • Last Post
Replies
1
Views
721
  • Last Post
Replies
3
Views
3K
Replies
2
Views
5K
  • Last Post
Replies
1
Views
538
  • Last Post
Replies
5
Views
966
  • Last Post
Replies
10
Views
1K
  • Last Post
Replies
7
Views
1K
  • Last Post
Replies
1
Views
868
Top