Solve 2 Physics Problems: Vectors, Hockey Puck Motion

AI Thread Summary
The discussion focuses on solving two physics problems involving vectors and hockey puck motion. For the first problem, participants clarify how to determine the x and y components of vectors using trigonometric functions, emphasizing the importance of distinguishing between displacement and velocity vectors. The second problem involves calculating the vertical and horizontal components of a hockey puck's motion, with participants discussing the significance of initial velocity and time to reach a target. There is an emphasis on showing effort before receiving assistance, and the need for clear understanding of the problem setup. Overall, the thread highlights the application of physics principles in vector analysis and projectile motion.
neutron star
Messages
78
Reaction score
1
1.

Homework Statement

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 = ____ °



Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
The rules of this forum clearly state
On helping with questions: Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given. Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.

Please follow them.
 
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.
 
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?
 
Make a drawing. Are there any negative components?
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top