One of the rectangular components of velocity of `80Kmh^(-1)` is `40Kmh^(-1)`. What is the other components?

Options

A. `40Kmh^(-1)`
B. `69.28Kmh^(-1)`
C. `89.44Kmh^(-1)`
D. `120Kmh^(-1)`

Answer

B

Explanation

`R= 80 km//h, R_(x)= 40 km//h`
but `R^(2)= R_(x)^(2)+R_(y)^(2)implies 80^(2)= 40^(2)+R_(y)^(2)`
`implies R_(y)^(2)= 4800`
`implies R_(y)= sqrt(4800)= 40 sqrt(3)= 69.28 km//h`