Projectile Motion ball is thrown upward

  • Thread starter creynaud
  • Start date
  • #1
4
0

Homework Statement


A ball is thrown upward at an angle of 30° to the horizontal and lands on the top edge of a building that is 20 m away. The top edge is 5.0 m above the throwing point. How fast was the ball thrown?

Homework Equations


xcos30
ysin30

The Attempt at a Solution


Im not sure what I am supposed to do considering there is no velocity given
 

Answers and Replies

  • #2
2,809
604
Im not sure what I am supposed to do considering there is no velocity given
How fast was the ball thrown?
Well, the problem is asking for the initial velocity, so its very natural that the initial velocity is not given to you!!!

Just take a look at the equations you have at hand and see which one has only one unknown, taking into account the data given in the problem.
 
  • #3
311
23
So the ledge coincides with the apex of the parabola
You also need the value for g (gravitational acceleration)
Youll be working on the vertical vector of the launch velocity first
 
  • #4
gneill
Mentor
20,945
2,886
So the ledge coincides with the apex of the parabola
Not necessarily. The projectile can land at the given spot after passing through its zenith.

Fig1.gif
 
  • #5
3,926
549
So the ledge coincides with the apex of the parabola
You also need the value for g (gravitational acceleration)
Youll be working on the vertical vector of the launch velocity first
This assumption is not implied by the text and is not necessary.
 
  • #6
311
23
Beyond me, sorry.
Dean
 

Related Threads on Projectile Motion ball is thrown upward

Replies
1
Views
3K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
3
Views
909
  • Last Post
Replies
22
Views
20K
  • Last Post
Replies
2
Views
2K
Replies
3
Views
3K
Replies
13
Views
15K
  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
5
Views
7K
Replies
13
Views
2K
Top