Sir/mam,the first part of the Q is easy
but the second part i'm not getting it as i feel it is the same qty but in the ans it is given that it is not..How?
It's not same quantity.
Check dimension. Vector have the dimension of velocity and the scaler have that of time.(time is scaler) thus the final vector will have dimension of distance and that is different quantity.
Yes sir i got it tysm.Then can we find its magnitude?
Yup. The magnitude can be found. Scaler can be directly multiplied to vectors.
Like :- ( i + j )(velocity) X 4 (time)= 4i + 4j (displacement)
Magnitude will be = root(x^2 + y^2) = 4root(2).
Thank you Sir.