[واحة العلوم]

A particle of mass 2kg is moving along a path with a position vector
المحصلة r = 5i + 10t j + 5t k


10t j هذه ال t ( أس -1)
Where t = time
a-find the velocity and acceleration vectors ؟
b- at what time t will the position and velocity vectors be prependicular .
c- what is the force acting on the body at t =2 sec