The problem involves a proton moving in a spiral path within a magnetic field of 5 T, with a specified pitch of 5 cm. The objective is to determine the angle between the velocity vector and the magnetic field vector.
Some participants have offered insights into the components of velocity and how they relate to the forces involved. There is recognition that additional information, such as speed or radius, is necessary to progress further in solving for the angle.
The problem is constrained by the information provided, which does not include values for speed or radius, making it challenging to find a definitive solution for the angle.
Basic_Physics said:That is it went 5 cm up or down after one revolution.
apelling said:The pitch of a spiral is the distance moved after one complete revolution.
The diagram in section 2.5 of this wiki article is fairly clear:-
http://en.wikipedia.org/wiki/Screw_thread
The two velocity components would be
vsinθ perpendicular to B
vcosθ parallel to B
vsinθ should be used in both the equations you give not just the first one.
The two forces can then be equated.
The pitch of the spiral is equal to vcosθ x (time period for one revolution, T) ie distance=speed x time
But T also is equal to 2πr/vsinθ.
Using the above ideas I found an expression for θ that still had one unknown in it. Is there any other information given in the question?