[填空题]
A charged particle $x$ enters a region of magnetic field $B$ of $2.0\,T$ with a speed of $3.5\times10^6\,ms^{−1}$ in the shown direction. The magnitude of the charge on the particle is $1.6\times10^{−19}\,C$.
1.Determine whether the particle is positive or negative. Justify your answer.
2.Calculate the magnitude of the force $F$ on this particle when it enters the magnetic field. F = $\times10^{-12}\,N$
A particle $y$ with an equal but opposite charge enters the same magnetic field $B$ as shown.
3.(1)If the ratio $\frac{v_x}{v_y}=\frac{1}{2}$, calculate the magnitude of the magnetic force on charge $y$. F = $\times10^{-12}\,N$
(2)Draw an arrow indicating the direction of the magnetic force on this particle when it just entered the magnetic field.
(3)Particle $y$ has the same mass as particle $x$, draw the path of particle y as it moves through the field.
