A race car completes a lap on a 1600 m long track with an average speed of 250 km/h. If the car's average speed on the first half of the track was 225 km/h, what was its average speed on the second half?

avg speed=distance/time

time for a lap=1.600/250 hr=.0064 hr

time for the first half lap=.800/225= .0035555 hr

time for second half lap= .0064-.0035555= .0028445

avg speed on second half= .8/.0028445 km/hr

This certainly is a small track for such high speeds.

284

To find the average speed on the second half of the track, we can use the average speed formula:

Average Speed (v) = Total Distance (d) / Total Time (t)

We know the average speed for the entire lap is 250 km/h, and the total distance is 1600 m. Let's convert the distance to kilometers first:

1600 m = 1600/1000 = 1.6 km

Now, let's calculate the total time taken for the lap using the average speed formula:

Total Time (t) = Total Distance (d) / Average Speed (v)

t = 1.6 km / 250 km/h = 0.0064 h

Next, we need to find the total time it took to complete the first half of the track. Since the average speed for the first half is given as 225 km/h, we can calculate the time using the same formula:

Time for First Half = Distance for First Half / Average Speed for First Half

The distance for the first half is half of the total distance, which is 1.6 km / 2 = 0.8 km. Now let's calculate the time:

Time for First Half = 0.8 km / 225 km/h = 0.00356 h

To find the time taken for the second half, we can subtract the time for the first half from the total time:

Time for Second Half = Total Time - Time for First Half

Time for Second Half = 0.0064 h - 0.00356 h = 0.00284 h

Finally, we can calculate the average speed on the second half of the track using the time and distance for the second half:

Average Speed for Second Half = Distance for Second Half / Time for Second Half

The distance for the second half is also 0.8 km, so let's calculate the speed:

Average Speed for Second Half = 0.8 km / 0.00284 h = 281.69 km/h

Therefore, the average speed on the second half of the track was approximately 281.69 km/h.

To find the car's average speed on the second half of the track, we first need to find the time it took to complete the first half.

We can use the formula: speed = distance / time rearranged to solve for time:

time = distance / speed

For the first half of the track:
distance = 800 m (half of 1600 m)
speed = 225 km/h

Converting the speed to meters per hour:
225 km/h = 225 * 1000 m / 1 km = 225,000 m/h

Plugging in the values:
time = 800 m / 225,000 m/h = 0.00356 h

Next, we need to find the time it took to complete the whole lap. Since the average speed for the entire lap is given as 250 km/h, we can use the same formula:

time = distance / speed

For the whole lap:
distance = 1600 m
speed = 250 km/h

Converting the speed to meters per hour:
250 km/h = 250 * 1000 m / 1 km = 250,000 m/h

Plugging in the values:
time = 1600 m / 250,000 m/h = 0.0064 h

Now, to find the time taken for the second half of the track, we subtract the time taken for the first half from the total time:

time for second half = total time - time for first half
= 0.0064 h - 0.00356 h
= 0.00284 h

Finally, we can find the average speed on the second half of the track using the formula:

speed = distance / time

For the second half:
distance = 800 m
time = 0.00284 h

Plugging in the values:
speed = 800 m / 0.00284 h = 281,690 m/h

So, the race car's average speed on the second half of the track is approximately 281,690 m/h.