A=29 B=39 C=139 D=12 3. Three particles travel through a region of space where the magnetic field is out of the page, as shown in the figure. What are the signs of the charges of these three particles? (10 points) 1 0 0 9 20 O O 4. In the figure, a small particle of charge -B x 10-6 C and mass m= D x 10"Pkg has speed vo= B x 10'm/s as it enters a region of uniform magnetic field. The particle is initially traveling perpendicular to the magnetic field and is observed to travel in the semicircular path shown with radius R = C/100 cm. Find the magnitude and direction of the magnetic field in the region. (15 points) Region of magnetic field Path of . the particle 5. A electron in a particle accelerator has a speed of B x 10 m/s towards +X Direction. The electron encounters a magnetic field whose magnitude is D/10 T and whose direction makes and angle of A degrees with respect to the electron's velocity. Find (a) the magnitude and direction of the force on the electron and (10 points) (b) the acceleration of the electron. (5 points) (c) What would be the force and acceleration of the particle were a neutron? (5 points) 6. a. What is the direction of the magnetic force on a negative charge that moves as shown in each of the cases shown? (15 points) X b. What is cross field? Provide an example? (10 points)