Question

Two cars leave the same place at the same time. One runs at 20 km/hr towards north and the other at 15km/hr towards east. What will be the distance between them ( in km ) after 2
hours of travelling ?
(A) 70
(B) 10
(C) 25
(D) 50

please give step by step explanation. ​

Answer 1

Answer:

Step-by-step explanation:

North and east are at 90 degree, equation becomes  

(

2

x

2

)

+

[

2

(

x

+

5

)

]

2

=

50

2

on solving, we get  

x

=

12.366

km/h

Answer 2

Answer:

50 meters

Step-by-step explanation:

so speed of one car going north is 20 km/h

speed of the other car going east is 15 km/h

car₁ distance = 20 kilometers/hour ˣ 2 hours = 40 km

car₂ distance = 15km/h ˣ 2 h = 30 km

total distance is 30 + 40 = 70 km

total displacement = shortest distance covered

so the displacement is diagonal since its the shortest distance between 2 points

so by using Pythagoras Theorem

30² + 40² = displacement²

900 + 1600 = displacement²

2500= displacement²

displacement = $\sqrt{2500}$

displacement = 50km

the actual distance is 50 kilometers