Question

One of the rectangular components of a vector 80 unit is 40 unit, the other component is

• A. 69 unit
• B. 60 unit
• C. 75 unit
• D. 36 unit.

Answer 1

Answer: (A)

69 unit

Answer 2

Here, $\upsilon$ = 80 km $h^{-1}$ Let $\upsilon_x$ = 40 km $h^{-1}, \upsilon_y = ?$ We know $\upsilon^2 = \upsilon^2_x + \upsilon^2_y$ $\upsilon^2_y = \upsilon^2 - \upsilon^2_x = 80^2 - 40^2$ $= 6400 - 1600 = 4800$ $\upsilon_y = \sqrt{4800}$= 69.28 unit .