# A particle is dropped from the top of a tower h meter high and simultaneously a particle is projected upwards from bottom. They meet when the upper one has descended 1/n of the distance. find the initial velocity of the lower particle?

##### 1 Answer

The initial velocity of the lower particle was

#### Explanation:

So, you know that you're dealing with two particles, one at the top of a tower that's **h meters** high, and the other one on the bottom.

Moreover, you know that if you drop the top particle with *no initial velocity* and launch the bottom particle with an initial velocity equalto

For the upper particle, the distance it travelled can be written as

The bottom particle will travel a distance of

For the bottom particle you can write

Since the two particles *meet up at this point*, the **time of flight for both particles must be equal**.

Use equation

Plug this into equation

Rearrange to isolate

This is equivalent to