A bird flies for `4 s` with a velcoty `v=t (-2) ms^(-1) in a stralght line. Calculate the displacement of the bird ans distance travelled by the bird.

Explanation

Vepcoty, ` v= (t -2)`
:. Acceleraton ` a =(dv)/(dt) = d/9dt) 9t-2) =1 ms^(23)`
When ` t-0, v_(0) =(0 -2) =- 2 ms^(-2)`
When ` t= 2 s, v= 2- 2 =0`
When ` t=4s, v=4 -2 =2 ms^(-1)`.
Taking motion of bird for time ` 0 to 2 s,` we have ` u =v_(0) =- 2 ms^(-1), a =1 ms^(-1)`,
`t= =2s, S= S_(1) (say) `
S= ut + 1/2 `
:. S_(1) =- 2 xx2 + 1/2 1xx 2^(2) =- 4 +2 =-2 m`
Taking motion of bird from ` 2 to 4 s`, we have
` u= o, a =1 ms^(-2), t=2 s, S=S^(2) 9say)`
S_(2) =0 xx 2 + 1/2 2^(2) =2 m`
:. Displacement in ` 4 s = S__(1) + S_(2) =-2 +2 =0`
Distance travelled in ` 4 s= |S_(1) |+ S_(2) `
`= 2 +2 =4 m`.