Speed conversion: kilometres per hour to metres per second:\nA missile travels at 1278 km/h. How many metres does it travel in one second?

Introduction / Context:
Convert km/h to m/s using the conversion 1 km/h = (1000/3600) m/s = (1/3.6) m/s. Multiply the speed by this factor to get metres per second, which is metres in one second.

Given Data / Assumptions:

• Speed v = 1278 km/h.

Concept / Approach:
m/s = km/h ÷ 3.6.

Step-by-Step Solution:

Verification / Alternative check:
Multiply back: 355 m/s × 3600 s/h = 1,278,000 m/h = 1278 km/h.

Why Other Options Are Wrong:
358, 345, 313, 330 are not equal to 1278/3.6.

Common Pitfalls:
Using 3.8 or 3.3 instead of 3.6, or forgetting to divide (not multiply) by 3.6.

Final Answer:
355 metres