A certain vector in the xy plane has an x component of 4 m and a y component of 10 m.It is then rotated in the xy plane so its x component is doubled.Its new y component is about:
A)20 m
B)7.2 m
C)5.0 m
D)4.5 m
E)2.2 m

Question

Quizplus · Accepted Answer

When the x component is doubled from 4 m to 8 m, the vector's magnitude remains the same. Using the Pythagorean theorem, the original magnitude is √(4² + 10²) = √116. The new y component can be found using √(8² + y²) = √116, solving for y gives approximately 7.2 m.

A Certain Vector in the Xy Plane Has an X