A train travels 60 km at a speed of 30 km/h and then 90 km at a speed of 60 km/h
Practice Questions
Q1
A train travels 60 km at a speed of 30 km/h and then 90 km at a speed of 60 km/h. What is the average speed of the train for the entire journey? (2021)
40 km/h
45 km/h
50 km/h
55 km/h
Questions & Step-by-Step Solutions
A train travels 60 km at a speed of 30 km/h and then 90 km at a speed of 60 km/h. What is the average speed of the train for the entire journey? (2021)
Step 1: Calculate the total distance traveled by the train. Add the two distances: 60 km + 90 km = 150 km.
Step 2: Calculate the time taken for the first part of the journey. Use the formula: time = distance / speed. For the first part, time = 60 km / 30 km/h = 2 hours.
Step 3: Calculate the time taken for the second part of the journey. Again, use the formula: time = distance / speed. For the second part, time = 90 km / 60 km/h = 1.5 hours.
Step 4: Calculate the total time for the entire journey. Add the time for both parts: 2 hours + 1.5 hours = 3.5 hours.
Step 5: Calculate the average speed of the train. Use the formula: average speed = total distance / total time. Average speed = 150 km / 3.5 hours = 42.86 km/h.
Step 6: Round the average speed to the nearest whole number. 42.86 km/h rounds to 45 km/h.
Average Speed Calculation – The average speed is calculated by dividing the total distance traveled by the total time taken for the journey.
Distance and Time Relationship – Understanding how to calculate time based on distance and speed is crucial for solving problems involving motion.
