The unit vector along $\hat i + \hat j$ is

If a unit vector is represented by $0.5\hat i + 0.8\hat j + c\hat k$, then the value of ‘$c$’ is

A plane covers $500 \,m$ in direction $60^o$ with run-way while starting the flight. Find the distance covered by plane in horizontal and vertical direction.

The change in a vector may occur due to .....

State with reasons, whether the following algebraic operations with scalar and vector physical quantities are meaningful :

$(a)$ adding any two scalars,

$(b)$ adding a scalar to a vector of the same dimensions ,

$(c)$ multiplying any vector by any scalar,

$(d)$ multiplying any two scalars,

$(e)$ adding any two vectors,

$(f)$ adding a component of a vector to the same vector.

Angular momentum is