Question

1. amy and penny are running in a race.

a. who has the greater displacement at the 20 s mark?
b. what time does penny reach the finish?
c. what time does amy reach the finish?
d. describe the motion of both penny and amy?

1. phoebe is pulling up to a stop light.

a. describe the motion of phoebes car.
b. why is the line on the graph curved?

Explanation:

Step1: Find displacement at 20s mark

On the position - time graph for Amy and Penny, at \(t = 20s\), Penny's position is higher (around 200m) and Amy's is lower (around 100m). So Penny has greater displacement.

Step2: Find Penny's finish - time

The finish - line seems to be around 350m. Reading from the graph, Penny reaches 350m at \(t = 35s\).

Step3: Find Amy's finish - time

Amy reaches 350m at \(t = 30s\).

Step4: Describe motion

Penny has a constant - speed motion as her position - time graph is a straight line, meaning her velocity is constant. Amy has an accelerated motion as her position - time graph is a curve, indicating her velocity is increasing.

Step5: Describe Phoebe's car motion

Phoebe's car is decelerating as it approaches the stop - light. The position - time graph is a curve that flattens out, indicating the speed is decreasing.

Step6: Explain the curved line

The line on Phoebe's graph is curved because the car's speed is changing (decreasing). A non - zero acceleration results in a curved position - time graph.

Answer:

a. Penny
b. 35s
c. 30s
d. Penny has constant - speed motion, Amy has accelerated motion

1. a. The car is decelerating.

b. The car's speed is changing (decreasing).