Answer to Question #143931 in Classical Mechanics for Fujai Muhammed

Question

Why can't the angle between force and displacement be 270 degrees in case of motion in a plane

Answer 1

$\text{If the angle } \alpha \text{ between vector and axis, then the projection of force}$

$\text { along axis is found as }\vec{F{pr}}=\vec{F}*cos{\alpha}$

$\vec{F{pr}}=\vec{F}*cos{\alpha}=\vec{F}*cos{270^0}=0$

$|\vec{F{pr}}|=0$

$\text{Therefore, the body does not move at this angle.}$

Answer: The body does not move at an angle of 270 to the applied force.