Two cars start from the same place at the same time at right angels to each other . Their speeds are 54 km/h and 72 km/h, respectively . After 20 seconds the distance between them will be ?
Answer & explanation
Correct answer: option 3
To convert km/h into m/sec .
X km/h × \(\frac{5}{18}\) = Y m/sec
54 km/h × \(\frac{5}{18}\) = 15 m/sec
72 km/h × \(\frac{5}{18}\) = 20 m/sec
Distance cover by both in 20 sec is 15 × 20 = 300 m , 20 × 20 = 400m
by using pythagoras theorem , we calculate distance between them after 20 sec.
Distance between them = 500 m