Add the components to get the resultant R = -42.55 **i** + 43 **j.** **Note F2 = 5.5 i + 0 j**
If you draw this you will find it lies in the second quadrant as the x coord is - ve and y +ve . Note that 43 / 42.55 gives tan of the angle between R and the -ve y axis. Thus tan inv (43 / 42.55) will give you this angle in radians. (Pi -this angle ) will give you the angle (+ve) with respect to the +ve X axis say theta.
The net force on the object, R will be given by
$\displaystyle R\ =\sqrt {(-42.55)^2\ +\ (43)^2}$ .
(b) You have the accln a (3.75) with initial vel u = 0 as it starts from rest
and the time t
Use $\displaystyle v\ =\ u\ +\ a\ t$ to get the final speed.
(c) The x component will be v cos theta and the y component will be v sin theta.
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Last edited by physicsquest; Sep 21st 2009 at 11:18 PM.
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