An electron that has velocity = ( m/s) + ( 3.0m/s) moves through the uniform magnetic field = . (a)Find the force on the electron due to the magnetic field. (b)Repeat your calculation for a proton having the same velocity.

A proton of charge +e and mass m enters a uniform magnetic field with an initial velocity . Find an expression in unit-vector notation for its velocity at any later time t.

Figure 28-27 shows the path of an electron that passes through two regions containing uniform magnetic fields of magnitudes and .

Its path in each region is a half-circle.

(a) Which field is stronger?

(b) What is the direction of each field?

(c) Is the time spent by the electron in the region greater than,

less than, or the same as the time spent in the region?

A long, rigid conductor, lying along an x axis, carries a current of in the negative direction. A magnetic field is present, given by with x in meters and in milliteslas. Find, in unit-vector notation, the force on the segment of the conductor that lies between and .

Question: In Fig. 28-57, the two ends of a U-shaped wire of mass m=10.0g and length L=20.0cm are immersed in mercury (which is a conductor).The wire is in a uniform field of magnitude B=0.100T. A switch (unshown) is rapidly closed and then reopened, sending a pulse of current through the wire, which causes the wire to jump upward. If jump height h=3.00m, how much charge was in the pulse? Assume that the duration of the pulse is much less than the time of flight. Consider the definition of impulse (Eq. 9-30) and its relationship with momentum (Eq. 9-31). Also consider the relationship between charge and current (Eq. 26-2).

Atom 1 of mass 35u and atom 2 of mass 37u are both singly ionized with a charge of +e. After being introduced into a mass spectrometer (Fig. 28-12) and accelerated from rest through a potential difference V=7.3kV, each ion follows a circular path in a uniform magnetic field of magnitude B=0.50T. What is the distance between the points where the ions strike the detector?