# Search results

1. ### Block and Spring (Simple Harmonic Motion Problem)

I figured out what I did wrong in this situation... cos-1(0) could be either pi/2 or -pi/2, and because the motion is coming to the end of a complete cycle I should have used -pi/2. To answer your question, I determined the phase shift=phi by solving the position equation. I knew at t=0...
2. ### Block and Spring (Simple Harmonic Motion Problem)

Homework Statement At t = 0 a block with mass M = 5 kg moves with a velocity v = 2 m/s at position xo = -.33 m from the equilibrium position of the spring. The block is attached to a massless spring of spring constant k = 61.2 N/m and slides on a frictionless surface. At what time will the...
3. ### Help with classical mechanics question

Momentum is always conserved in a closed system-that is, if there are no external forces that could effect the situation. Hope that helps!
4. ### Kinematics Final Velocity Question

very happy to help:D
5. ### Kinematics Final Velocity Question

because the velocity is downward it is negative, as well as the acceleration. you can't interchange them. it is just important to note the direction of the velocity depending on the equation you decide to use!
6. ### Kinematics Final Velocity Question

also correct! acceleration is -9.8 m/s2. something to think about--what is the direction of the velocity?
7. ### Kinematics Final Velocity Question

exactly! 2 m/s would be the initial velocity.

9. ### Kinematics Final Velocity Question

Is the initial velocity 66 or 68 m/s? If it is 68 m/s, your answer is very close to mine---I'm sure just rounding differences. Just double check the problem.
10. ### Question involving tension

right on! very good.
11. ### Kinematics Final Velocity Question

This equation is fine to use, but you will have to solve for acceleration (you have the initial and final velocities, plus the time!) Once you solve for acceleration, you can solve for the displacement over time.
12. ### Conservation of Energy Possibly

k=spring constant so it is accounted for. the negative sign is correct, but you also have to take into consideration that you will be taking the square root of the magnitude of the work. the negative simply implies direction--the spring is being compressed.
13. ### Conservation of Energy Possibly

**solve for the x value where W=1/2kx^2!! sorry that was not very clear
14. ### Conservation of Energy Possibly

okay here are my thoughts... you were right in thinking that this is a conservation of energy problem, or at least that is what I did too. we know that the work done by the spring is equal to 1/2kx2, and we also know that work is defined as force times distance. you can solve for the force of...
15. ### Conservation of Energy Possibly

i'm working on it so you know that someone has seen it!
16. ### Question involving tension

Think about Newton's 2nd law...draw a free body diagram of the situation. because they want the answer in variables, don't consider the magnitude of the acceleration!
17. ### Inclined plane w/ friction problem

this looks good to me!
18. ### Finding distance using vector components

the beauty of unit vectors is that it already takes the angle into consideration! all you have to do in this case is add the i vectors with i vectors and js with js.
19. ### Finding distance using vector components

here's some reading for you to do that should help! http://www.physics.uoguelph.ca/tutorials/vectors/vectors.html
20. ### Coefficient of friction of a ramp

Thank you so much for the help!
21. ### Coefficient of friction of a ramp

That is exactly as the problem is written, the only thing I forgot to include was that we are looking for the coefficient of friction. Sorry about that!
22. ### Coefficient of friction of a ramp

Homework Statement A student has two ramps, both of which are at an angle of 30o. Ramp 1 is frictionless and ramp 2 has friction. The student also has two blocks, one for each ramp. She pushes the blocks up the ramps with the same initial velocity. The block on ramp 2 only travels a...