Question

directions: for each of the following, write the letter of the term or phrase that best completes the sentence.

1. the speed of a motorcycle at a particular moment is its ____ speed.

a. average b. constant c. instantaneous

1. two cars are each traveling at 72 km/h. one car is traveling northeast, and the other is traveling south. the two cars have different ____.

a. distances b. speeds c. velocities

1. displacement and distance are only equal when an object moves in ____.

a. a circle b. a straight line c. opposite directions

1. when graphing motion, if the slope of swimmer a is steeper than swimmer b, then swimmer a is going ____ swimmer b.

a. faster than b. slower than c. the same speed as

1. a sprinter runs 200 m west and 100 m east. her displacement is ____.

a. zero meters b. 300 m c. 100 m west
directions: look at the graph. match the letters in the graph to the sentences below. graph of ruths motion

1. she walks at a constant speed of 80 m/min.
2. ruth stops for 10 minutes to speak to a friend.
3. she jogs 600 m in 5 minutes.

directions: the distance - time graph below shows the motion of a student walking to a convenience store for a loaf of bread and returning home. use the graph to answer questions 9 through 13.

1. in which two segments was the student moving at the fastest rate of speed?
2. in which segment might the student be waiting for a traffic light?
3. which segment indicates that the student might be stopped at the convenience store?
4. in which segment was the student moving at the slowest rate of speed?
5. which took longer, walking to the store or walking home?

Explanation:

1. Instantaneous speed is the speed at a particular moment.
2. Velocity is speed with direction, so cars with same speed but different directions have different velocities.
3. Displacement and distance are equal when an object moves in a straight - line.
4. Steeper slope in a distance - time graph means faster speed.
5. Displacement is the straight - line distance from start to end point, so 200 m west and 100 m east gives a displacement of 100 m west.

6 - 13: In a distance - time graph, constant speed is a straight - line non - horizontal segment, zero speed is a horizontal segment, and steeper segments mean faster speed.

Answer:

1. C. instantaneous
2. C. velocities
3. B. a straight line
4. A. faster than
5. C. 100 m west
6. (No options given for this part in the answer - choice format, but it corresponds to a non - horizontal straight line segment on the graph)
7. (No options given for this part in the answer - choice format, but it corresponds to a horizontal segment on the graph)
8. (No options given for this part in the answer - choice format, but it requires identifying the steepest segments on the graph)
9. (No options given for this part in the answer - choice format, but it requires identifying the steepest segments on the graph)
10. (No options given for this part in the answer - choice format, but it corresponds to a horizontal segment on the graph)
11. (No options given for this part in the answer - choice format, but it corresponds to a horizontal segment on the graph)
12. (No options given for this part in the answer - choice format, but it corresponds to a horizontal segment on the graph)
13. (No options given for this part in the answer - choice format, but it requires comparing the time taken for different segments on the graph)