A motorist travels 90 km at 120km/h , and 70km at 75km/h . What is the average speed for the trip?
To find the average speed for the entire trip, you need to calculate the total distance traveled and the total time taken.
Step 1: Calculate the time taken for each part of the trip.
For the first part of the trip:
Distance = 90 km
Speed = 120 km/h
Time = Distance / Speed = 90 km / 120 km/h = 0.75 hours
For the second part of the trip:
Distance = 70 km
Speed = 75 km/h
Time = Distance / Speed = 70 km / 75 km/h = 0.9333 hours (rounded to 4 decimal places)
Step 2: Calculate the total distance and total time for the entire trip.
Total Distance = 90 km + 70 km = 160 km
Total Time = 0.75 hours + 0.9333 hours = 1.6833 hours (rounded to 4 decimal places)
Step 3: Calculate the average speed for the trip.
Average Speed = Total Distance / Total Time = 160 km / 1.6833 hours = 95.0845 km/h (rounded to 4 decimal places)
Therefore, the average speed for the entire trip is approximately 95.0845 km/h.
To calculate the average speed for the entire trip, you need to find the total distance traveled and the total time taken. Then you can divide the total distance by the total time to get the average speed.
First, let's find the total distance traveled. The motorist traveled 90 km at 120 km/h and 70 km at 75 km/h, so the total distance is:
Total distance = 90 km + 70 km = 160 km
Next, we need to find the total time taken for the trip. To do this, we divide the distance traveled by the speed for each leg of the trip and sum up the individual times.
For the first leg of the trip, the motorist traveled 90 km at a speed of 120 km/h. Therefore, the time taken for the first leg is:
Time taken for the first leg = Distance / Speed = 90 km / 120 km/h = 0.75 hours
For the second leg of the trip, the motorist traveled 70 km at a speed of 75 km/h. Therefore, the time taken for the second leg is:
Time taken for the second leg = Distance / Speed = 70 km / 75 km/h = 0.93 hours
Now, we can find the total time taken for the whole trip by adding up the individual times:
Total time taken = Time taken for the first leg + Time taken for the second leg = 0.75 hours + 0.93 hours = 1.68 hours
Finally, to calculate the average speed, we divide the total distance by the total time:
Average speed = Total distance / Total time taken = 160 km / 1.68 hours ≈ 95.24 km/h
Therefore, the average speed for the entire trip is approximately 95.24 km/h.