Question

PHYSICS

Read the passage given below carefully and answer the questions based on it:

Rohan and Anirban are students of the same school that is 18 km away from their hostel. One

day, they started from their hostel at the same time with an initial velocity of 28.8 km/hr. At

this speed, it would take 20 min for them to reach the school on time. After 5 min, Rohan

stopped due to some problem in his cycle. Anirban didn't wait for him and moved forward.

Rohan took another 5 min to repair his cycle. He again started with the same initial velocity

as he started from the hostel.

1. At what distance from their hostel did Rohan stop?

2. What is the required acceleration for Rohan to reach his school on time when he started the

second time?

3. What is the difference between distance travelled and displacement in reference to above

passage?

4. With what acceleration Anirban covers the distance from hostel to school?

5. What will be their final velocity once both will reach the school?

6. What will be the value of displacement covered by Anirban in going from hostel to school

and returning back to hostel after dispersal from school? Explain with reason.

7. With what acceleration Rohan was moving before the problem occurred in his cycle? What

do you observe after finding its value?​

Answer 1

Answer:

Explanation:

Given,

Distance from Hostel to School = 18 KM

Initial velocity = 28.8 km/hr

Time required for cover distance = 20 min

Formula For Speed is

speed = distance/time

Now,

1. At what distance from their hostel did Rohan stop?

Ans : Rohan stop after 5 min of run,

So, we need to calculate distance cover in 5 min with velocity 2808 km/hr

So,

Speed = distance/time

i.e. distance = speed x time

i.e. distance = 28.8 * (5/60)     ... covert min into hr

                    = 2.4 km

So, 2.4 km from their hostel did Rohan stop.

4. With what acceleration Anirban covers the distance from hostel to school?

Ans :

Anirban covers the distance from hostel to school in 20 min.

distance = 18 KM

time = 20 min

speed = distance/time

           = 18KM/(20/60)    ...convert min into hr.

           = 54 km/h

So, Anirban covers the distance from hostel with average 54 km/h