2 Dimensional Kinematics Part 7 Acceleration in Two

2 -Dimensional Kinematics Part 7: Acceleration in Two Dimensions

Consider This: Determine which scenarios involve acceleration. You are skating forward at an increasing speed. A bird is taking flight, rising higher and going faster in the air. A cyclist slows to a stop. A transport truck maintains a constant speed while turning. Recall that acceleration is defined at the rate of change in velocity, which is a vector. The result of this definition is: Acceleration occurs when an object’s direction of travel changes.

Consider This:

Subtracting Vectors

Try These:

Consider This: What relationship between the directions of the two vectors (positive and negative) did you notice in the examples above?

Finding Acceleration in Two-Dimensions

Example: You maintain a constant speed of 85 km/h as you use the on-ramp to enter the highway. Your direction changes from North to East in the span of 2. 1 s. Determine the average acceleration over that time in m/s 2.

What if? . . . When the directions involved are more complicated, we rely on angle rules. Recall the angle rules

Example: A dancer changes velocity from 3. 1 m/s [E 22°N] to 4. 8 m/s [S 18°W]. Determine the average acceleration that occurs over 1. 1 s.