Two dimensional physics problem

  • Thread starter svtec
  • Start date
  • #1
22
0
In a snowball fight 2 snowballs are thrown in the same direction, but one is thrown 70.0 degrees with respect to the horizontal and the other is thrown some arbitrary distance lower. they both are thrown with a speed of 25.0 m/s.

At what angle should the one that is thrown lower be to arrive at the same point as the one that was thrown at 70.0 degrees?

How many seconds later should the lower thrown snowball be thrown to arrive at the same time as the higher one.

resolving into x and y components for the first one i get.

x initial = 0
x final =?
v initial = 25.0cos(70.0)
v final = 0 m/s
a = 0 m/s^2

y initial = 0
y final = ?
v initial = 25.0sin(70.0)
v final = 0m/s
a = -9.80m/s^2

then i get lost...


tia....


-andrew
 

Answers and Replies

  • #2
Doc Al
Mentor
44,987
1,259
What makes you think "v final = 0 m/s"?
 
  • #3
22
0
i figured that when the snowball made contact with the target it's velocity would be 0.
 
  • #4
FZ+
1,561
3
As someone who has been hit often by snowballs before, I can reassure you that as the ball hits you, it is definitely not stationary. (You are confused with collision modelling here, I think. The velocity after it hit is presumeably zero. But not as it hits/just before it hits.)

What you want to do is to use the uniform acceleration equations in each case to work out an expression for time taken in each case for the ball to fall to the ground, and then insert this to find out the horizontal distance travelled for each, and equate the two distances to find the angle.
 
  • #5
22
0
i am kinda confused. this is my first quarter in physics and i seem to confuse the moment before collision and the stationary component of the final velocity. i guess that is why i was enlisting the help of people that are far more superior in their understanding of physics then myself...

i'll give what you said a shot.

thanks...

-andrew
 

Related Threads on Two dimensional physics problem

  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
2
Views
9K
  • Last Post
Replies
1
Views
929
  • Last Post
Replies
1
Views
612
  • Last Post
Replies
0
Views
3K
  • Last Post
Replies
16
Views
3K
Replies
5
Views
545
  • Last Post
Replies
3
Views
6K
Replies
4
Views
7K
Top