# Two Physics problems

1. Oct 4, 2009

### neutron star

1.

The problem statement, all variables and given/known data

Determine the x and y components of the following three vectors in the xy plane.
(a) A 9-m displacement vector that makes an angle of 35° clockwise from the +y direction.
x: ____ m
y: ____ m

(b) A 25-m/s velocity vector that makes an angle of 45° counterclockwise from the -x direction.
x: ____ m/s
y: ____ m/s

(c) A 49-lb. force vector that makes an angle of 140° counterclockwise from the -y direction.
x: ____ lb
y: ____ lb

2.

You are watching your friend play hockey. In the course of the game, he strikes the puck in such a way that, when it is at its highest point, it just clears the surrounding 2.84 m high Plexiglas wall that is 10.8 m away. (Ignore any effects due to air resistance.)
(a) Find the vertical component of its initial velocity.
v0y = ____ m/s

(b) Find the time it takes to reach the wall.
Δt = ____ s

(c) Find the horizontal component of its initial velocity, and its initial speed and angle.
v0x = ____ m/s
v0 = ____ m/s
θ = ____ °

2. Relevant equations

3. The attempt at a solution

2. Oct 4, 2009

### kuruman

The rules of this forum clearly state

3. Oct 4, 2009

### neutron star

Ok, I need help with the first one. I'm trying to set it up but I don't get what it's asking for. Can you help explain?

Ok, I figured it out, I set it up on paper and got it.

4. Oct 4, 2009

### neutron star

I got the first one. I saw to get x you do sin(35) and then multiply by 9. And the same with y but cos instead of sin. I did the same thing for (b) in the first problem and it wasn't right. It's a velocity vector instead of a displacement vector. What difference does thi make for finding the solution?

5. Oct 4, 2009

### kuruman

Make a drawing. Are there any negative components?