Question

Alyssa is learning to drive her parents' car. • • • • She increases her speed for 20 seconds. She slows down for 10 seconds. She stays approximately the same speed for the next 20 seconds. She then slows down to a stop for the last 5 Select the graph that best seconds. represents Alyssa's speed over time

Answer 1

Answer: Choice D

Explanation:

Any time Alyssa is increasing her speed, the graph will move uphill when going from left to right.

If she slows down, then the graph will move downhill when going left to right.

Always move from left to right when reading a graph because this is how the time axis is set up.

Any flat part represents portions where her speed is constant, i.e. doesn't change.

With all that in mind, the answer is choice D because

• The first portion is going uphill (she's increasing her speed). This portion spans horizontally from 0 seconds to 20 seconds.
• The next portion is her slowing down (the graph is going downhill). This portion spans horizontally from 20 seconds to 30 seconds (so we have a 10 second duration).
• The third portion is where Alyssa is driving at some fixed speed that doesn't change. This portion is 20 seconds long.
• The last portion is Alyssa slowing down and coming to a complete stop. This portion is 5 seconds long.