Question

1. it took 3 hours for a train to travel a straight track between two cities at a speed of 120 miles/hr. the train made 2 stops along the way. how far apart are the two cities? is the train accelerating? explain.

answer: 360miles

1. a girl selling newspapers is pedaling her bike at a speed of 5 miles per hour. she travels for 2 hours and makes two left hand turns during her journey. how far did she travel? is she accelerating? explain.

answer: 10mile changes direction

1. an ant carries food at a speed of 2 cm/s. how long will it take the ant to carry a cookie crumb from the kitchen table down to the floor and up to the ant hill, a distance of 2400 cm away? is the ant accelerating? explain.

answer:

1. nascar fans love race day when they get a chance to cheer on their favorite team. if the driver was able to travel 600 miles on the oval track in 3 hours, what was his average speed? is he accelerating? explain.

answer:

1. the water in the comal river flows at an average speed of 5 km/hr. if you and a friend decide to go on the river for a distance of 25 km, how many hours will it take you to complete the journey? if you started at 9 am, what time would you finish?

answer:

Explanation:

Step1: Calculate distance for ant problem

Use formula $t=\frac{d}{v}$, where $d = 2400$ cm and $v=2$ cm/s.
$t=\frac{2400}{2}=1200$ s. Since the ant may change speed or direction during the journey, it is accelerating.

Step2: Calculate average - speed for NASCAR problem

Use formula $v=\frac{d}{t}$, where $d = 600$ miles and $t = 3$ hours.
$v=\frac{600}{3}=200$ miles/hr. On an oval - track, the driver's direction is constantly changing, so he is accelerating.

Step3: Calculate time for river - journey problem

Use formula $t=\frac{d}{v}$, where $d = 25$ km and $v = 5$ km/hr.
$t=\frac{25}{5}=5$ hours. If starting at 9 am, finish at 2 pm.

Answer:

1. 1200 s; Yes, as it may change speed or direction.
2. 200 miles/hr; Yes, as direction is changing on oval - track.
3. 5 hours; 2 pm