Group Problems Physics 2424 Here are some questions to help you prepare for Friday's assessment quiz, Notevery subject here will be on the exam and it is possible that subjects not listed here might be on the exam, but overall, this should be a helpful review, Answer as many as you can during the class period, The comments in parentheses provide an explanation of what concepts are being explored On the exam any subject could be asked using a qualitative question, a quantitative question, or a ratio problem, as appropriate, 1, A negatively charged particle is moving west in a region where there is a magnetic field pointing north, What direction is the force on the particle" What direction(s) could the particle be moving so that there would be no force on it (Know how to use RUR-I for positively and negatively charged objects and when there will be no magnetic force on an object.) 2. A particle with a charge of 4.5 at is moving west at a speed of 6,500 m/s in a region where there is a magnetic field of 0.10 T pointing at an angle of 25" west of north. What is the magnitude and direction of the force on the particle? (Calculate the magnitude and direction of the magnetic force) A particle with a charge of 4.5 DC' is moving west at a speed of 6,500 m/s in a region where there is a magnetic field of 0.30 T pointing north. If there is also an electric field in the same region and the particle is moving straight, what is the magnitude and direction of the electric field? (Use magnetic force in conjunction with electric force, or with other forces in Newton's 2" law). 4. A charged particle with a mass of 0.5 grams is moving at a constant speed of 750 m/s in a circular path with a radius of 12 m in a region of space where there is a 1.2 T magnetic field perpendicular to the plane of the circle, What is the charge of the particle? (Solve problems with magnetic force and Newton's 2" law including centripetal acceleration and know), 5. A 1.5 m horizontal wire with a current of 15 A north is suspended in air by a 2.0 T magnetic field pointing west. What is the mass of the wire? (Solve problems with the magnetic force on a wire with a current and use that force in problems involving Newton's 2"d law). A 1.5 m horizontal wire with a current of 15 A north is suspended in air because another wire is placed 1.0 em above the first wire and has a current of 10 A flowing through it. What is the mass of the lower wire and what direction is the current flowing in the top wire? (Solve problems with the magnetic force between two wires, each with a current, and use that force in problems involving Newton's 2" law). 7. A horizontal wire has a current flowing north. What is the direction of the magnetic field made by this wire at a point (a) east of the wire. (b) above the wire, (e) west of the wire, (d) below the wire. (Understand the magnitude and direction of the magnetic field made from a long straight wire). 8. One wire has a current of 1.2 A flowing north. A second wire is placed parallel to the first wire and 20 em to the east and has a current of 1.8 A flowing south, What is the total magnetic field from these two wires at a location 10 em above the first wire? (Add magnetic fields form wires, or from loops of wire, as vectors). 9. What direction is the magnetic field inside this loop of wire with the current flowing in the direction shown? (Use RHR-3 to determine the direction of a magnetic field in a loop of wire or in a solenoid) 10. A square wire loop with sides of 0.15 m has 25 turns and is place in a magnetic field of 2.4 T. A current of 9.8 A flows in the wire loop. At one point in time the loop feels a torque of 29 N.m. What is the angle between the magnetic field and a line drawn perpendicular to the plane of the wire loop? (Know how wire loops interact in a magnetic field and how that creates a motor)