how to find what speed her new train must go to be the second fastest in this group

Question

1.    Ellen works for a high-speed rail company that wants to develop a new rail line. Ellen’s project is to find a train that is the second fastest in the world. The Shinkansen Bullet Train in Japan is reported to go as fast as 320 kilometers per hour. The TGV train in France can reach speeds of 89.44 meters per second. Explain to Ellen how to find what speed her new train must go to be the second fastest in this group. Then, find an appropriate speed for Ellen’s train in miles per hour and use the formula distance = speed • time to find how far the train can go in 2.5 hours. Use complete sentences and show your work.

Answer 1

Speed of Bullet train= 320 x(1000/3600) m/s  = 88.89 m/s      (to convert km into m multiply by 1000 and to                                                                                                      convert hour in seconds multiply by 3600)

Speed of TGV train = 89.44 m/s

 

In order for Ellen's train to be second highest speed, its speed should lie between the range 88.89 m/s and 89.44 m/s

 

Hence, the range of the distance of the ellen's train can be calculated. It is not possible to find out the specific distance unless we are given with specific speed of the train.

 

Distance traveled by Bullet train= Speed x time= 88.89 m/s x (2.5 x 3600)sec = 800,010m= 800.01km

Distance traveled by TGV train  =Speed x time=  89.44 m/s x (2.5 x 3600)sec = 804,960m= 804.96 km

 

Therefore, the distance traveled by ellen's train should lie between the range of 800.01-804.96 km

Answer 2

To be able to compare the speeds of the two trains, you must first make sure the units are the same. The Bullet Train speed is in kilometers per hour, but the TGV speed is in meters per second. Knowing that there are 1000 meters in a kilometer, and 3600 seconds in an hour, you can convert that speed and compare them. Once you have these two speeds, you know that in order for Ellen's train to be the second fastest, it has to be slower than the faster one, but faster than the slower one. 

 

For example, if Train A goes 350 kph, and Train B goes 875 kph, to be the second fastest, you need to go less than 875 kph but more than 350 kph. So 400kph would be appropriate, as would 800kph.

 

When using distance=speed*time, you also have to make sure your units are correct. You should have your train speed in hours, so you don't need to convert anything this time. But in the case that you have both of your speeds in meters or kilometers per second, don't forget to convert seconds to hours.

 

Hope that helps!

Answer 3

320 km/hr x 1000m/km x 1 hr/3600s = 88.89 m/s

 

Ellen's train must go between 88.89 m/s and 89.44 m/s