Physicshard · Past Paper
A ship A is moving Westwards with a speed of 10 km/h and a ship B 100 km South of A, is moving Northwards with a speed of 10 km/h. The time after which the distance between them becomes shortest is:
A5 h
B5√2 h
C10 h
D0 h
✓ Correct Answer: A — 5 h
Using relative velocity, min distance occurs at t = (initial distance * v_rel) / (v_rel_sq). For this geometry, it is 5 hours.
Share this question
More from Physics
- A particle has an initial velocity of 3i + 4j and an acceleration of 0.4i + 0.3j. Its speed after 10s is:
- When a wave reflects from a rigid boundary, there is a phase change of:
- A wire of resistance R is stretched to double its original length while keeping volume constant. What is its new resistance?
- A body moves from A to B with 40 km/h and returns with 60 km/h. Its average speed is:
- Calculate the equivalent resistance of the network where two 4-Ohm resistors are in parallel, and this combination is in series with a 2-Ohm resistor.