At a state fair truck pull, two pickup trucks are attached to the back end of a monster truck as illustrated in the figure. One of the pickups pulls with a force of 1600 pounds and the other pulls with a force of 3200 pounds with an angle of 45° between them. With how much force must the monster truck pull in order to remain unmoved? [HINT: Find the resultant force of the two trucks].

Answer 1

Can't see your diagram, but it looks like a straightforward cosine law
R^2 = 1600^2 + 3200^2 - 2(1600)(3200)cos 135°
R = ....

Answer 2

Thank you for helping me set this up Reiny.

Answer 3

Fr = 1600[0o] + 3200[45o] =
1600 + 2263+2263i = 3863 + 2263i =
4477N[30.4o] N. of E.