Question

sarita and julie walking from the sone place in the opposite directions if julie walks at a speed of 2¹/²km/h and sarita at a speed of 2 km/h,in how much time will they be 18 km a part.​

Answer 1

$\bigstar$ Given

Sarita and Julie start walking from the same place in the Opposite directions. If Julie walks at a speed of 2.5 km/h and Sarita at a speed of 2 km/h

$\bigstar$ To Find

How much time will they be 18 km apart

$\bigstar$ Solution

Relative speed in opposite direction

$\red{\sf \longrightarrow V_{rel}=V_{A}+V_{B}}$

• $\sf V_{rel}$ = relative velocity in opp. direction
• $\sf V_{A}$ = velocity of A
• $\sf V_{B}$ = velocity of B

Given that

Sarita and Julie start walking from the same place in the Opposite directions. If Julie walks at a speed of 2.5 km/hr and Sarita at a speed of 2 km/hr

Hence

$\blue{\sf \longrightarrow 2.5 \ km/h + 2 \ km/h = 4.5 \ km/h}$

Therefore

$\star$ Speed (v) = 4.5 km/h

We know that

$\orange{\sf \longrightarrow t=\dfrac{d}{v}}$

Here

• t = time
• d = distance
• v = speed

According to the question

We are asked to find how much time will they be 18 km apart

Therefore

We must find "t"

Given that

Sarita and Julie start walking from the same place in the Opposite directions. If Julie walks at a speed of 2.5 km/h and Sarita at a speed of 2 km/h. How much time will they be 18 km apart

Hence

• d = 18 km

We found out

• v = 4.5 km/h

Substituting the values

We get

$\green{\sf \longrightarrow t=\dfrac{18 \ km}{4.5 \ km/h}}$

$\blue{\sf \longrightarrow t=\dfrac{18}{4.5} \ h}$

On further simplification

We get

$\pink{\sf \longrightarrow t=4 \ h}$

Therefore

Time (t) = 4 hours

Hence

After 4 hours they will be 18 km apart