# Recent content by vysis

1. ### Speed of light questions

hm... becuase I have a spacetime diagram modeling this answer and it seems that it is only supposed to be 12 seconds....
2. ### Speed of light questions

btw, this is all from signal sender's frame of reference.
3. ### Speed of light questions

the ship is moving in the positive direct and is at 0 ls when t = 0
4. ### Building a car without a mousetrap! i'm desperate!

use styrofoam (or something equally light), stick a fan on the back. Add wheels. Voila.

a fan?
6. ### Speed of light questions

Homework Statement A signal (traveling at the speed of light) is sent from -4 ls (light seconds) towards a moving spaceship traveling at 0.866c. How long does it take for the signal to reach the ship? Homework Equations I'm pretty sure its t=(delta)D/c-v But I continue to get the...
7. ### Friction problem again Okay today is not my day

but I'm not given the train's acceleration... am I missing something here =/?
8. ### Friction problem again Okay today is not my day

Homework Statement A passennger is standing without slipping in a forward accelerating train. The coeffeciant of the feet and the floor is 0.47. Determine the maximum required acceleration of the train relative to the track if the passenger is not to slip Homework Equations F=ma The...
9. ### Simple but unsure, compound questions

omg, how did I miss that 0_0 thank you, everything is 100% clear now =P
10. ### Simple but unsure, compound questions

isn't the equation (mu)mg? mu = F/N right? So therefore F=(mu)N -> F = (mu)mg?
11. ### Incline and Firction (again!)

Solved, thanks guys
12. ### Incline and Firction (again!)

thats the thing though... it doesn't give you the mass. It ONLY gives you the force of kinetic friction and the initial speed
13. ### Incline and Firction (again!)

Homework Statement A skier on a slope inclined at 4.7 degrees from the horizontal starts down the slope with an initial speed of 2.7m/s. The coefficient of friction is 0.11. Determine how far the skier will slide before coming to a rest. Homework Equations Fnet=ma F(f) = (mu)N The...
14. ### Simple but unsure, compound questions

Basically: givens v(1) = 0m/s F(t) = 21N (31 degree) (mu kinetic) = 0.5 (mu static) = 0.55 a = 0m/s^2 X component Fnet=ma F(t) - F(f) = ma F(t) = (mu)Mg m = F(t) / (mu)g m= 18N / 0.55*9.8 m = 3.3kg Y Component F(net) = ma F(t) = Fg F(t) = m/g m = 21Sin31 / 9.8 m =...
15. ### Simple but unsure, compound questions

A boy is pulling on a box at a 31 degree angle using 21N of force. The box remains stationary. The co-efficient of static friction is 0.55. What is the minimum mass? When I use the component method to solve this problem, do I need to calculate the mass for both the Horizontal and the Vertical...