Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.

A sample dot-product problem

A particle of dust of mass m = 2 x 10^(-3) kg has an initial speed v = 2 m/s.

An electric field inside the lab exerts a force 


          F       =  12 mN  i   -    6 mN  j    +   8 mN  k

on a small dust particle. As the particle moves through the room, its location changes from 



 initial pos  r1  =  1.2 m  i  +   0.3 m  j   +   0.6 m  k
to 


 final   pos  r2  =  3.5 m  i  -   1.2 m  j   -   0.1 m  k

  1. What is the work done on the dust particle by the electric force?
  2. What is the work done on the dust particle by the gravitational force?
  3. What is the change in the dust particle's kinetic energy?
  4. What is the dust particle's final speed?

Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.