Question

In order to qualify for the finals in a racing event, a race car must achieve an average speed of 257 km/h on a track with a total length of 1660 m. Of a particular car covers the first half of the track at an average speed of 243 km/h, what minimum average speed must it have in the second half of the event in order to qualify

Answer 1

Answer:272.711b km/h

Step-by-step explanation:

Given

Average speed of car must be 257 km/h

and first half is covered by a speed of 243 km/h

and rest by, let say by v

average speed

`V_(average)=(total distance)/(total time)`

`257=(1660)/(t_1+t_2)`

Where
`t_1=(830)/(257)`

`t_2=(830)/(v)`

`257=(1660)/((830)/(257)+(830)/(v))`

`(1)/(243)+(1)/(v)=(2)/(257)`

`(1)/(v)=(2)/(257)-(1)/(243)`

v=272.711 km/h