Question

A ship A is moving Westwards with a speed of
10 kmh-1 and a ship B 100 km South of A, is
moving Northwards with a speed of 10 kmh the
shortest distance between them is
(1) 10/2
(2) 10/3
(3) 50/2
(4) 50/3​

Answer 1

Answer:

give some explanation and with diagram

Explanation:

option 4is correct

Answer 2

answer : option (1) 10/2 h

explanation : ship A is moving westward with a speed 10km/b and ship B, which located 100km south from A, is moving northward with a speed 10km/h as shown in figure.

we know, shortest distance between two points is displacement between them.

so, here it is clear that shortest distance between A and B is perpendicular distance PQ ( displacement).

PQ = ABcos45° = 100 × 1/√2 = 50√2 km

velocity A with respect to B = -10i - 10j

so, magnitude of relative velocity , v = √(10² + 10²) = 10√2 km/h

now time taken = PQ/v = 50√2/10√2 = 5h

hence, option (1) 10/2 h is correct choice.