Question

1. In a tug-of-war game, 12 children pull on two sides of a rope. Define right as +x and left as –x. On the right, there are two children each pulling with a force of 122 N, one pulling with a force of 86 N, and three each pulling with a force of 102 N. On the left, there is one child pulling with a force of 180 N, two each pulling with a force of 90 N, and three each pulling with a force of 110 N. Using unit-vector notation, express the total force on the center of the rope.

2. A mail carrier parks her postal truck and delivers packages. To do so, she walks east at a speed of 0.80 m/s for 4.0 min, then north at a speed of 0.50 m/s for 5.5 min, and finally west at a speed of 1.1 m/s for 2.8 min. Define east as +x and north as +y.

(a) Write unit-vector velocities for each of the legs of her journey.

(b) Find unit-vector displacements for each of the legs of her journey.

(c) Find her net displacement from the postal truck after her journey is complete.

3. Vector A points in the positive y-direction and has a magnitude of 7.0 cm. When it is added to vector B, the resultant vector C has a magnitude of 18 cm and is at an angle of 120º. Find the components of vector B.

Answer 1