A spy plane is being tacked by a radar. At `t`=0, its position is reported as (100`m` ,200`m`, 1000`m`). 130`s` later, its position is reported to be (2500`m`,1200`m` ,1000 `m`). Find a unit vector in the direction of plane velocity and the magnitude of its average velocity.

Answer

`20 ms^(-1);(12hat(i)+5hat(j))/13`;

Explanation

In 13 `s`, the displacement is
`(2500-100)hat(i)+(1200-200)hat(j) +(100-100)hat(k)=2400hat(i)+1000hat(j)`
Manitude of displacement `sqrt((2400)^(2)+(1000)^(2))=2600`
`:. Velocity =2600/130=20m s^(-1)`
And unit vector along velocity `=1/2600(2400hat(i)+1000hat(j))=(12hat(i)+5hat(j))/13`