A flat metal plate of mass is released from rest at the upper edge of a uniform…

PHYSICS · Single correct · AP · Physics C: Mechanics · Force and Translational Dynamics · Force and Translational Dynamics

Problem

A flat metal plate of mass mm is released from rest at the upper edge of a uniform magnetic field. While within the field, the retarding force on the plate is proportional to its instantaneous speed, F=kvF = k v, where kk is a constant. Ignoring air resistance, which expression gives the speed v(t)v(t) of the plate after time tt? (a) mgk e−(k/m)t\dfrac{mg}{k}\, e^{-(k/m) t} (b) mgk(1+e−(k/m)t)\dfrac{mg}{k}\left(1+ e^{-(k/m) t}\right) (c) mgk(1−e−(k/m)t)\dfrac{mg}{k}\left(1- e^{-(k/m)t}\right) (d) mgk(1−e−(k/2m)t)\dfrac{mg}{k}\left(1- e^{-(k/2m)t}\right)

Related theory

Browse the problem library