
Concept explainers
(a)
The direction of the force on the projectile.
(a)

Answer to Problem 122P
The force on the projectile is
Explanation of Solution
The right hand rule states that in the case of a cross product, if the index finger of the right hand points in the direction of the first vector and the second vector points in the direction of the middle finger, then the cross product will point in the direction of the thumb. Magnetic force on a current carrying wire is the product of the current through the wire and the cross product of the vector, whose magnitude is the length of the wire and is points in the direction of current, and the magnetic field.
Right hand rule for the magnetic force on a current carrying conductor can be described as if the index finger of the right hand points in the direction of current, the middle finger in the direction of the magnetic field, then the thumb will point in the direction of the magnetic force. In the given situation, the current flows into the page and the magnetic field is directed upward. According to the right hand rule, the magnetic force on the projectile is directed to the right.
(b)
The speed of the projectile after it has travelled
(b)

Answer to Problem 122P
The speed of the projectile after it has travelled
Explanation of Solution
The free body diagram of the projectile is shown in figure 1.
The rod only moves in the
Here,
Refer to figure 1 and write the expression for
Here,
Equate equations (I) and (II).
Write the equation for the force of kinetic friction.
Here,
Put equation (III) in the above equation.
Apply Newton’s second law to the rod for the motion in
Here,
Refer to figure (I) and write the expression for
Here,
Put the above equation in equation (V) and rewrite it for
Write the expression for
Here,
Put equations (IV) and (VII) in equation (VI).
Write the second law of motion.
Here,
The rod starts from rest so that its initial speed is zero.
Substitute
Put equation (VIII) in the above equation.
Conclusion:
Given that the mass of the projectile is
Substitute
Therefore, the speed of the projectile after it has travelled
Want to see more full solutions like this?
Chapter 19 Solutions
Physics
- Find the amplitude, wavelength, period, and the speed of the wave.arrow_forwardA long solenoid of length 6.70 × 10-2 m and cross-sectional area 5.0 × 10-5 m² contains 6500 turns per meter of length. Determine the emf induced in the solenoid when the current in the solenoid changes from 0 to 1.5 A during the time interval from 0 to 0.20 s. Number Unitsarrow_forwardA coat hanger of mass m = 0.255 kg oscillates on a peg as a physical pendulum as shown in the figure below. The distance from the pivot to the center of mass of the coat hanger is d = 18.0 cm and the period of the motion is T = 1.37 s. Find the moment of inertia of the coat hanger about the pivot.arrow_forward
- Review Conceptual Example 3 and the drawing as an aid in solving this problem. A conducting rod slides down between two frictionless vertical copper tracks at a constant speed of 3.9 m/s perpendicular to a 0.49-T magnetic field. The resistance of th rod and tracks is negligible. The rod maintains electrical contact with the tracks at all times and has a length of 1.4 m. A 1.1-Q resistor is attached between the tops of the tracks. (a) What is the mass of the rod? (b) Find the change in the gravitational potentia energy that occurs in a time of 0.26 s. (c) Find the electrical energy dissipated in the resistor in 0.26 s.arrow_forwardA camera lens used for taking close-up photographs has a focal length of 21.5 mm. The farthest it can be placed from the film is 34.0 mm. (a) What is the closest object (in mm) that can be photographed? 58.5 mm (b) What is the magnification of this closest object? 0.581 × ×arrow_forwardGiven two particles with Q = 4.40-µC charges as shown in the figure below and a particle with charge q = 1.40 ✕ 10−18 C at the origin. (Note: Assume a reference level of potential V = 0 at r = ∞.) Three positively charged particles lie along the x-axis of the x y coordinate plane.Charge q is at the origin.Charge Q is at (0.800 m, 0).Another charge Q is at (−0.800 m, 0).(a)What is the net force (in N) exerted by the two 4.40-µC charges on the charge q? (Enter the magnitude.) N(b)What is the electric field (in N/C) at the origin due to the two 4.40-µC particles? (Enter the magnitude.) N/C(c)What is the electrical potential (in kV) at the origin due to the two 4.40-µC particles? kV(d)What If? What would be the change in electric potential energy (in J) of the system if the charge q were moved a distance d = 0.400 m closer to either of the 4.40-µC particles?arrow_forward
- (a) Where does an object need to be placed relative to a microscope in cm from the objective lens for its 0.500 cm focal length objective to produce a magnification of -25? (Give your answer to at least three decimal places.) 0.42 × cm (b) Where should the 5.00 cm focal length eyepiece be placed in cm behind the objective lens to produce a further fourfold (4.00) magnification? 15 × cmarrow_forwardIn a LASIK vision correction, the power of a patient's eye is increased by 3.10 D. Assuming this produces normal close vision, what was the patient's near point in m before the procedure? (The power for normal close vision is 54.0 D, and the lens-to-retina distance is 2.00 cm.) 0.98 x marrow_forwardDon't use ai to answer I will report you answerarrow_forward
- A shopper standing 2.00 m from a convex security mirror sees his image with a magnification of 0.200. (Explicitly show on paper how you follow the steps in the Problem-Solving Strategy for mirrors found on page 1020. Your instructor may ask you to turn in this work.) (a) Where is his image (in m)? (Use the correct sign.) -0.4 m in front of the mirror ▾ (b) What is the focal length (in m) of the mirror? -0.5 m (c) What is its radius of curvature (in m)? -1.0 marrow_forwardAn amoeba is 0.309 cm away from the 0.304 cm focal length objective lens of a microscope.arrow_forwardTwo resistors of resistances R1 and R2, with R2>R1, are connected to a voltage source with voltage V0. When the resistors are connected in series, the current is Is. When the resistors are connected in parallel, the current Ip from the source is equal to 10Is. Let r be the ratio R1/R2. Find r. I know you have to find the equations for V for both situations and relate them, I'm just struggling to do so. Please explain all steps, thank you.arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON





