scientists have theorized using long conducting wire, the space station must be ____ relative to a _____ field a) stationary, magnetic b) moving, magnetic c) stationary, gravitational d) moving, gravitational

A particle in the cyclotron shown in Figure 28.16a gains energy qV from the alternating power supply each time it passes from one dee to the other. The time interval for each full orbit is T=2=2mqB so the particles average rate of increase in energy is 2qVT=q2BVm Notice that this power input is constant in time. On the other hand, the rate of increase in the radius r of its path is not constant. (a) Show that the rate of increase in the radius r of the panicles path is given by drdt=1rVB (b) Describe how the path of the particles in Figure 28.16a is consistent with the result of part (a). (c) At what rate is the radial position of the protons in a cyclotron increasing immediately before the protons leave the cyclotron? Assume the cyclotron has an outer radius of 0.350 m, an accelerating voltage of V = 600 V, and a magnetic field of magnitude 0.800 T. (d) By how much does the radius of the protons path increase during their last full revolution? Figure 28.16 (a) A cyclotron consists of an ion source at P, two does D1 and D2 across which an alternating potential difference is applied, and a uniform magnetic field. (The south pole of the magnet is not shown.) (b) The first cyclotron, invented by E. O. Lawrence and M. S. Livingston in 1934.

Measurements at the weak and ?uctuating magnetic fields associated with brain activity are called magnetoencephalograms (MEGS). Do the brain’s magnetic fields imply coordinated or uncoordinated nerve impulses? Explain.

Neurons in our bodies carry weak currents that produce detectable magnetic fields. A technique called magnetoencephalography, or MEG, is used to study electrical activity in the brain using this concept This technique is capable of detecting magnetic fields as weak as 1.0 1015 T. Model the neuron as a long wire carrying a current and find the current it must carry to produce a field of this magnitude at a distance of 4.0 cm from the neuron.

Integrated Concepts The Tethered Satellite discussed in this module is producing 5.00 kV, and a current of 10.0 A flows. (a) What magnetic drag force does this produce if the system is moving at 7.80 km/s? (b) How much kinetic energy is removed from the system in 1.00 h, neglecting any change in attitude or velocity during that time? (c) What is the change in velocity if the mass of the system is 100,000 kg? (d) Discuss the long term consequences (say, a week-long mission) on the space shuttle’s orbit, noting what effect a decrease in velocity has and assessing the magnitude of the effect.

A cosmic ray electron moves at 7.50106m/s perpendicular to the Earth's magnetic field at an altitude where field strength is 1.00105T. What is the radius of the circular pain the electron follows?

A proton moves at 7.50107m/s perpendicular to a magnetic field. The field causes the proton to travel in a circular path of radius 0.800 m. What is the field strength?

An electron in a TV CRT moves with a speed at 6.00107m/s, in a direction perpendicular to the Earth’s field, which has a strength of 5.00105T. (a) What strength electric field must be applied perpendicular to the Earth’s field to make the election moves in a straight line? (b) If this is done between plates separated by 1.00 cm, what is the voltage applied? (Note that TVs are usually surrounded by a ferromagnetic material to shield against external magnetic fields and avoid the need for such a correction.)

A cyclometer is a device mounted on a bicycle that records and displays trip information such as elapsed time, distance traveled, and average speed. Modern versions employ small magnets attached to a spoke on either the front or rear wheel and a sensor located on the front fork or rear frame. As the magnet is carried past the detector once each wheel revolution, it produces an electrical pulse that is recorded and logged by an integrated circuit in the device. The distance traveled equals the total number of revolutions multiplied by the circumference of the wheel. (a) A typical mountain bike has a wheel diameter of 26 in. How far will a cyclist have traveled in both miles and kilometers if her cyclometer indicates that her front wheel has made 25,000 revolutions during her trip? (b) If the cyclometer clock shows that the elapsed time for the trip was 2 hours and 40 minutes, what was the rider’s average speed during this period?

What is the maximum force on an aluminum rod with a 0.100C charge that you pass between the poles of a 1.50T permanent magnet at a speed of 5.00 m/s? In what direction is the force?