- #1
wcjy
- 73
- 10
- Homework Statement
- A mass m with a small charge q slides from rest on a rough incline which is at an
angle theta to the horizontal. The coefficients of static friction and kinetic friction are
denoted by U_s and U_k respectively. A magnetic field B is directed out of the page
(see Figure 8(a)).
(ii) Derive an expression for U_k when the mass is accelerating with acceleration a and moving with speed v.
- Relevant Equations
- f = uN
When the mass starts sliding down, it will induce a current due to the cutting of B field.
By fleming right-hand rule, the B field points into the field, charge going in the direction down the ramp (current pointing down the ramp?),
therefore the force should be in the same direction of normal.
However, the answer seems to suggest that the magnetic force is acting opposite from the normal. Is my understanding wrong for the direction of current?
The picture below shows the answer: