Init. A almatien
Quiz 1
As shown in the figure below, Justin walks from the house to his truck on a windy day. He walks 20 m
toward the truck, 15 m back to retrieve his wind-blown hat, and another 20 m to reach the truck. He
walked a total time of 75 s.
20 m
15 m
20 m
What is Justin's average velocity over the 75 s period?

v = 1/3 m / s = 0.333 m / s

in the direction of the truck

Explanation:

The average speed is defined by the variation of the position between the time spent

           v = Δx / Δt

since the position is a vector we must add using vectors, we will assume that the displacement to the right is positive, the total displacement is

           Δx = 20 - 15 +20

           Δx = 25 m

therefore we calculate

         v = 25/75

         v = 1/3 m / s = 0.333 m / s

in the direction of the truck

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

the components of a vector are the parts of the vectors that are to each other.

b perpendicular