1. The problem statement, all variables and given/known data An electron in a cathode-ray tube is accelerated through a potential difference of 10 kV, then passes through the d = 2.4-cm-wide region of uniform magnetic field in the figure(Figure 1) . What field strength will deflect the electron by θ = 13 degrees? 2. Relevant equations Δx=vt+0.5aΔt2 KE=0.5mv2 U=qΔV F=qvBsin(θ) F=ma B=ma/qvsin(θ) Ki+Ui=Kf+Uf 3. The attempt at a solution Since Ki=0, then Kf=-ΔU Since U=qΔV, then Kf=-qΔV Since Kf=0.5mv2, then 0.5mv2=-qΔV Using 0.5mv2=-qΔV, and inputing values 0.5(9.11×10-31)v2)=-(-1.60×10-19)(10,000) So, v after acceleration by ΔV is 5.931×107 m/s. Δx=viΔt+0.5axΔt2 Since ax=0, because the force should be acting to change only the ay t=4.047×10-10 s so, Δy=viΔt+0.5ayΔt2 and since Δy=0.024tan(13)=5.54×10-3 then, ay=6.765×1016 Since: F=qvBsin(θ) and F=ma, then B=ma/qvsin(θ), and θ=90, (I think?) so B=(9.11×10-31)(6.756×1016)/(1.60×10-19)(5.931×107)=6.49×10-3 T This answer is incorrect. Could someone show me where I went wrong? Thanks!