3 trig questions help please!!?
Solve each of the following problems. Choose from the answers given at the bottom.
1. Two forces of 692 and 423 newtons act on a point. The resultant force is 786 newtons. Find the angle between the forces.
2. Find the force required to push a 100-lb box up a ramp inclined 10º with the horizontal.
3. A force of 25 lb is required to push an 80-lb lawn mower up a hill. What angle does the hill make with the horizontal?
A) 17.36lb
B) 93.91º
C) 18.21º
1)the two forces can be thought of as < 692,0> and < 423 cos Θ , 423 sin Θ> , so the resultant is the sum of these. The magnitude of the sum vector is 786.
[ 692 + 423 cos Θ ] ² + [423 sin Θ]² = 786²
692² + 2*692*423 cos Θ + 423² = 786²
solve for cos Θ , then Θ
2)assuming no friction { not stated} all you need to do is overcome the force component on the ramp...{ 100 cos 80° }
3)same ideas as the 2nd...25 = 80 cos [90° - Θ] , solve for Θ...given the choices the answer must be c ...a in in pounds , b is ridiculous
