Answer:

Explanation:
Here two charges are placed at distance "d" apart
now the net value of electric field at some position between two charges will be ZERO
so we will have
electric field due to charge 1 = electric field due to charge 2

Let the position where net field is zero will lie at distance "r" from q1

now we will have

now square root both sides

now we have

so we have

Answer:
Velocity of airplane is 500 km/h
Velocity of wind is 40 km/h
Explanation:
= Velocity of airplane in still air
= Velocity of wind
Time taken by plane to travel 1150 km against the wind is 2.5 hours

Time taken by plane to travel 450 km against the wind is 50 minutes = 50/60 hours

Subtracting the two equations we get

Applying the value of velocity of wind to the first equation

∴ Velocity of airplane in still air is 500 km/h and Velocity of wind is 40 km/h
You are correct. Mountains are part of the lithosphere.