Assuming the gravity to be in negative z -direction, a force`vecF =vecV xx vecA` is exerted on a particle in addition to the force of gravity where `vecV` is the velocity of the particle and `vecA` is a constant vector in positive x - direction. What minimum speed a particle of mass in be projected so that it continues to move undeflected with constant velocity?

Explanation

`|vecF| =vA sin theta`
Here, `theta` is angle between `vecv` and `vecA` The particle moves undeflected if `vecF` acts be in positive z-direction. Hence, veloicty should be in negative y-direction.
or `vecV_("min") =-(mg)/A hatj`