PDA

View Full Version : i & j Vector Question


ZedCar
Mar6-10, 06:44 PM
Have I done this correctly? Thank you.

1. The problem statement, all variables and given/known data
A particle of mass 2kg moves under the action of forces 3i - 12j, and i + 6j.

(i) Find the resultant force acting on the particle in the form ai + bj
(ii) Find the acceleration of the particle



2. Relevant equations
F = ma


3. The attempt at a solution

(i)
R = 3i + i - 12j + 6j
R = 4i - 6j

(ii)
Using F = ma
4i - 6j = 2a
2i - 3j = a

asquared = 2squared + (-3)squared
a = square root of (4 + 9)
a = square root of 13

Doc Al
Mar6-10, 06:49 PM
Looks good. (But don't leave out units. Physical quantities require units.)

ZedCar
Mar6-10, 07:07 PM
Thanks very much Doc! :smile:

Looks good. (But don't leave out units. Physical quantities require units.)

Yes, forgot to type the units in. Thanks