3.1 Position, Displacement, and Average Velocity

Give an example in which there are clear distinctions among distance traveled, displacement, and magnitude of displacement. Identify each quantity in your example specifically.

Bacteria move back and forth using their flagella (structures that look like little tails). Speeds of up to 50 μm/s (50 × 10⁻⁶ m/s) have been observed. The total distance traveled by a bacterium is large for its size, whereas its displacement is small. Why is this?

Does a car’s odometer measure distance traveled or displacement?

A car is 2.0 km west of a traffic light at t = 0 and 5.0 km east of the light at t = 6.0 min. Assume the origin of the coordinate system is the light and the positive x direction is eastward. (a) What are the car’s position vectors at these two times? (b) What is the car’s displacement between 0 min and 6.0 min?

The position of a particle moving along the x-axis is given by $x \left(t\right) = 4.0 - 2.0 t$ m. (a) At what time does the particle cross the origin? (b) What is the displacement of the particle between $\text{t} = 3.0 \text{s}$ and $\text{t} = 6.0 \text{s} ?$

On February 15, 2013, a superbolide meteor (brighter than the Sun) entered Earth’s atmosphere over Chelyabinsk, Russia, and exploded at an altitude of 23.5 km. Eyewitnesses could feel the intense heat from the fireball, and the blast wave from the explosion blew out windows in buildings. The blast wave took approximately 2 minutes 30 seconds to reach ground level. The blast wave traveled at 10° ab…