Question

iii. whats the scenario read each short scenario carefully. decide which vocabulary word best fits the situation and write your answer on the line provided. be sure to use each term only once.
word bank:
speed motion reference point displacement distance
time acceleration velocity rate of change
a. a car speeds up from a stoplight and begins moving faster each second. what vocabulary word describes this change?
b. a jet flies north at 600 km/h, then turns west but keeps the same speed. what is changing?
c. a runner covers 200 meters in 25 seconds. what describes how fast she is moving?
d. a line on a graph becomes steeper as an objects velocity increases quickly. what does this represent?
e. a baseball rolls across the field toward first base. what is happening to the ball?
f. you watch a moving train while standing next to a stop sign. the stop sign helps you tell that the train is moving. what is the stop sign called?
g. a cyclist rides 10 miles on a trail from start to finish. what is being measured?
h. a student walks around the track and ends up where she started. what is her final measurement called?
i. a stopwatch shows how long it takes a rocket to reach the sky. what quantity being measured?
iv. whats the word? choose any vocabulary word and give the definition (in your own words) one characteristic, one example, and one non - example.

Explanation:

• a. Acceleration is the rate of change of velocity. When a car speeds up (increases its velocity), it is accelerating.
• b. Velocity is a vector quantity (has both magnitude and direction). The jet changes direction (from north to west) while speed (magnitude) remains the same, so velocity is changing.
• c. Speed is calculated as \(speed=\frac{distance}{time}\). Here, we are finding how fast (speed) the runner is moving using the formula with given distance (\(200\) meters) and time (\(25\) seconds).
• d. In a velocity - time graph, the slope of the line represents the rate of change of velocity. A steeper slope means a greater rate of change (acceleration).
• e. Motion is a change in position. The baseball rolling across the field is changing its position, so it is in motion.
• f. A reference point is an object used for comparison to determine if another object is in motion. The stop sign is used to tell if the train is moving, so it is a reference point.
• g. Distance is the total length of the path traveled. The cyclist rides \(10\) miles (total path length), so distance is being measured.
• h. Displacement is the change in position from the starting point to the ending point. The student ends up where she started, so displacement is \(0\) (but the term for the measurement of the change in position is displacement).
• i. A stopwatch measures the duration between two events, which is time.

Answer:

a. acceleration
b. velocity
c. speed
d. rate of change
e. motion
f. reference point
g. distance
h. displacement
i. time