An electron starts from rest and is accelerated through a potential difference V. The electron moves in a path perpendicular to the magnetic field B. The path of the electron makes a circle of radius R. Which of the following gives the formula for the charge to mass ratio (e/m) of the electron?

a. e/m= 2V/B^2. R^2
b. e/m= B^2R^2/2V
c. e/m= 2VB^2/R^2
d. e/m= R^2/ 2VB^2
e. e/m = 2VR^2/ B^2
f. e/m= B^2/ 2VR^2
g. e/m= 2VB^2R^2
h. None of these

The plum pudding model of the atom states that ?

Suppose you have a box. which of these is not necessarily a true statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? a. if the box is not moved, no force is being applied to the box. b. if no force is applied to the box, no work is done on the box. c. if work is done on the box, then a force is applied to the box. d. if work is done on the box, then the box is moved a distance.

What is the gravitational attraction between a dating couple whose centers of mass are 0.630 m apart if the boy weighs 715 n and the girl weighs 465 n?