Problem 555 part a a bag of groceries is on the seat

Problem 5.55
Part A
A bag of groceries is on the seat of your car as you stop for a stop light. The bag does not slide. Draw a free­body diagram for the bag.
Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be
graded but the relative length of one to the other will be graded.
ANSWER:
18
More than 18
0
Less than 18 but greater than 0
Typesetting math: 100%

9/6/2016 Homework3­2
9/21
Correct
Mechanical Equilibrium Problems
A pair of students are lifting a heavy trunk on move­in day. Using two ropes tied to a small ring at the
center of the top of the trunk, they pull the trunk straight up at a constant velocity . Each rope
makes an angle with respect to the vertical. The gravitational force acting on the trunk has
magnitude .
The trunk is moving at a constant velocity. This means that you can model it as a particle in dynamic equilibrium. Furthermore, you can ignore the masses of
the ropes and the ring because it is reasonable to assume that their combined weight is much less than the weight of the trunk.
Part A
The most convenient coordinate system for this problem is one in which the y axis is vertical and the ropes both lie in the xy plane, as shown below.
Identify the forces acting on the trunk, and then draw a free­body diagram of the trunk in the diagram below. The black dot represents the trunk as it is
lifted by the students.
Draw the vectors starting at the black dot. The location and orientation of the vectors will be graded. The length of the vectors will not be
graded.
ANSWER:
Typesetting math: 100%

9/6/2016 Homework3­2
Correct
Part B
In the free­body diagram drawn in the previous part, different symbols are used to represent the tensions in the two ropes. This notation could be simplified
by identifying a useful relationship between these two forces. Which of the following statements properly describes the relationship between the magnitude
of the tension force in rope 1 and the magnitude of the tension force in rope 2?
10/21
Correct
This is a type of reasoning, used often in physics, called a symmetry argument . Since the ropes are in identical situations, except for one being the
mirror image of the other, they have to possess identical tensions. Since the two tension forces have equal magnitude, just use to denote the
magnitude of the tension force in either rope. With the information you have gathered here, you can build a complete pictorial representation:
Part C