contestada

A race car is one lap behind the lead race car when the lead car has 55 laps to go in a race. If the speed of the lead car is 62.3 m/s, what must be the average speed of the second car to catch the lead car just before the end of the race (i.e., right at the finish line)

Respuesta :

pmdislamabad

Answer:

The second car must go with a speed of 63.43 m/sec

Explanation:

Speed V of lead car = 62.3 m/sec

Distance S =   55 laps = 55 ×400 meters=22000 m

We know

S = V × t

So,

t= S/V

We put values of S and V here, we get

t=22000/62.3

t= 353.1 sec

So in 353.1 sec the second car which is one lap behind - must go a distance of 55+1=56 laps or 56×400 m = 22400 meters to catch the lead car before it finishes.

i-e for second car

Distance S= 22400m

Time t = 353.1 sec

V= ?

using again

S=Vt

we get

V= S/t

V= 22400/353.1= 63.43 m/sec

Otras preguntas