Two forces are applied to a car in an effort to move it, as shown in Figure P4.12.(adsbygoogle = window.adsbygoogle || []).push({});

Here's Figure P4.12: <img src="http://www.webassign.net/sercp/p4-12.gif"/> [Broken]

(a) What is the resultant of these two forces?

Magnitude: N

Direction: Degrees (measured to the right from the forward direction)

(b) If the car has a mass of 3000 kg, what magnitude acceleration does it have? Ignore friction.

For part A, I found F1 = (400cos30)i + (400sin30)j

F2 = (450cos10)i + (450sin10)j

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Fnet=[346i + 443i] + [200j + 78.1j]

Fnet= 789i + 278.1j

I then used the Pythagoreon Thereom to figure out the resultant force. I got 837 N. However, webassign.net says this is wrong and I've been re-doing the problem over and over and get the same answer.

I used tan-1 [278/789] for the angle and got 19.4 degrees but webassign.net also tells me this is the wrong answer.

Finally, for part B, I used F=ma and used 837=3000a and solved for a. I got a=.279 m/s^2 but again webassign.net tells me this wrong.

So, basically, I was hoping someone could look through my work and tell me if you can figure out what I'm doing wrong cause I could swear I did this correctly.

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# Homework Help: Two people pulling a car please help.

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