E1t3 Retake Preap 2016

Explanation
The speed of an object at rest is 0.0 m/s because when an object is at rest, it is not moving and therefore has no speed or velocity. Speed is defined as the distance traveled per unit of time, and if there is no distance traveled, the speed is zero. In this case, since the object is at rest, it is not moving and its speed is 0.0 m/s.

Explanation
In this scenario, the cat is moving downwards from a higher position (tree limb) to a lower position (ground). Since the positive position is measured vertically upward along the y-axis, any movement in the opposite direction (downward) represents a negative displacement. Therefore, option d is the correct answer as it represents a negative displacement.

Explanation
The correct answer is b. xi = +3 m. This statement is true because xi represents the initial position of the toy car, and in this case, it starts at +3 m.

Explanation
A change of position farther to the left of zero indicates that the object has moved in the negative direction, or to the left. Displacement refers to the change in position, and since the object has moved to the left, the displacement is negative. Therefore, the correct answer is d. negative displacement.

Explanation
The distance traveled by an object can be calculated by multiplying the average velocity by the time of motion. In this case, for option II, the average velocity is +3.0 m/s and the time of motion is 2.0 s, resulting in a positive distance traveled. For option I, the average velocity is -4.0 m/s and the time of motion is 2.0 s, resulting in a negative distance traveled. For option III, the average velocity is -3.0 m/s and the time of motion is 3.0 s, resulting in a negative distance traveled. Therefore, the correct order of distances traveled in increasing order is II, I, III.