A car travels for 6 hours at different speeds. For the first two hours at 60 m/s, for the next 2 hours at 50 m/s and for the remaining time at x m/s. If the average speed for the entire journey is 52 m/s, what is the value of x?
Answer & explanation
Correct answer: option 1
1 hour = 3600 seconds
Distance = Speed × Time
Total distance = (60 + 50 + X)×7200 m
We know,
Average speed = \(\frac{Total\; Distance}{Total \; Time }\)
According to question ,
52 = \(\frac{(110 + x) × 7200}{6 × 3600}\)
52 = \(\frac{(110 + x) }{3}\)
110 + x = 52 × 3
x = 156 – 110
x = 46 m/sec
So , Value of x is 46 m/sec