Two spheres with uniform surface charge density, first with a radius of 7.5cm and the second with a radius of 4.9cm , are separated by a center-to-center distance of 33 cm. the spheres have a combined charge of +55%u03bcc and repel one another with a force of 0.65n . assume q1> q2.
(a) what is the surface charge density on the first sphere? (c/m^2)
(b) what is the surface charge density on the second sphere? (c/m^2)

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

Very large accelerations can injure the body, especially if they last for a considerable length of time. one model used to gauge the likelihood of injury is the severity index ( ), defined as =/ . in the expression, is the duration of the accleration, but is not equal to the acceleration. rather, is a dimensionless constant that = the number of multiples of that the acceleration is equal to.in one set of studies of rear-end collisions, a person's velocity increases by 13.7 km/h with an acceleration of 36.0 m/s2 . let the + direction point in the direction the car is traveling. what is the severity index for the collision?

What happens when you slowly pulled the carboard?