Hi there!
We can use the following equation for a point charge in a magnetic field:
[tex]\large\boxed{F_B = qv \times B}[/tex]
[tex]F_B[/tex] = Force due to magnetic field (7.6 × 10⁻¹³N)
[tex]q[/tex] = Charge of particle (1.6 × 10⁻¹⁹ C)
[tex]v[/tex] = velocity of particle (6.6 × 10⁶ m/s)
[tex]B[/tex] = Magnetic field strength (1.8 T)
Or, without the cross product:
[tex]F_B = qvBsin\theta[/tex]
θ = angle between particle's velocity and field
We can rearrange to solve for theta:
[tex]\frac{F_B}{qvB} = sin\theta\\\\\theta = sin^{-1} (\frac{F_B}{qvB})[/tex]
Solve for theta:
[tex]\theta = sin^{-1} (\frac{7.6*10^{-13}}{(1.6*10^{-19})(6.6*10^6)(1.80)}) = \boxed{23.57^o}[/tex]
