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

Projectile Motion of spear throw

  • Thread starter iwan97
  • Start date
  • #1
16
1

Homework Statement


Man is throwing a spear at distance of 100m away from a building. Window is at the height of 50m. At which angle and velocity man has to throw spear? Spear must be parallel to ground when going through a window.

I can figure out this one. I usually first calculate time in the air but it doesn't work in this one.

I split all data and variables in horizontal and vertical direction so it would be something like this:

Horizontal

x0=0m
x=100m
a=0m/s2
vox=cosα*v0


Vertical

y0=0m
y=50m
a=-9.81m/s2
v0y=sinαv0
 

Answers and Replies

  • #2
124
3
This is quite late but i'm still posting my answer: In this question range and maximum height of the projectile are already given. To get the angle, you can do this by finding the relation between range and maximum height, which is: range is twice of maximum height.Solving the relation, you would get the angle. To find initial velocity, you just need to apply the formula of either range or maximum height.
p.s. It's my first actual answer on this forum. Hope it helped☺.
 
  • #3
16
1
3 months late mate :)
I found the answer my self but thanks for posint anyways!
 
  • #4
CWatters
Science Advisor
Homework Helper
Gold Member
10,528
2,294
The management actually encourages people to answer as many unanswered questions as possible even if late because they still show up in searches. Over 120 people viewed this thread since it was originally posted.
 

Related Threads for: Projectile Motion of spear throw

  • Last Post
Replies
8
Views
8K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
3
Views
1K
Replies
4
Views
12K
  • Last Post
Replies
2
Views
15K
  • Last Post
Replies
10
Views
3K
  • Last Post
Replies
4
Views
2K
Replies
52
Views
15K
Top