# After 2 seconds of flight,the velocity of a projectile is (12i-4j)m/s,Find its speed and elevation at moment of projection?

##### 2 Answers

When a projectile is projected with an initial speed of

But, the vertical component of velocity i.e

So,suppose,after

So,in vector form we can write,velocity after

So,comparing with the given equation,we can say,

Solving the above two equations we get,

#### Answer:

where

#### Explanation:

Let's set t=0 at the moment of projection, and denote

Substitute the above into the y(t) equations

Because,

Substitute