# Mechanics: Vectors and Forces in Two-Dimensions

## Vectors and Forces in 2-D: Audio Guided Solution

#### Problem 19:

Mom and Dad have tied a rope to Matthew’s sled and are momentarily pulling him through the snow. Dad is pulling with force A and Mom with force B.

A: 54 N at 65° north of east
B: 130 N at 22° south of east

a. Determine the resultant force of A and B.
b. Determine the acceleration that these momentary forces would create for a 39-kg sled and child (assuming negligible friction).

## Audio Guided Solution

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## Habits of an Effective Problem Solver

• Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
• Identify the known and unknown quantities in an organized manner. Equate given values to the symbols used to represent the corresponding quantity - e.g., m = 1.25 kg, µ = 0.459, vo = 0.0 m/s,  Ø = 41.6º, vf = ???.
• Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
• Identify the appropriate formula(s) to use.
• Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.