Hint:Thrust is the force acting on a body ‘perpendicular’ to its surfaces. The quantity thrust contains both magnitude and direction. Scalar quantity is a quantity that has only magnitude and no direction.
Let us first understand what a scalar quantity and a vector quantity are. A scalar quantity is a quantity that has only magnitude. Scalar quantities do not have any direction. For example, mass. Mass is quantity that has only magnitude and no direction. A vector quantity is a quantity that has both magnitude as well as direction.
For example, force. Force is a quantity that has a magnitude and we apply a force we have to also consider its direction. Now, let's understand what thrust is and relate it to the above information.As said in the hint, thrust is the force applied perpendicular to the surface of a body. Since a force contains both magnitude and direction, it is considered as a vector quantity.
Therefore, thrust is a vector quantity.
Note:Pressure is defined as thrust per unit area on a surface. This means that pressure exerted on a surface is equal to the thrust on the surface divided by the area of the surface. Note that pressure is not a vector quantity just because it involves a force. When we calculate the pressure on a surface, we only consider the magnitude of the thrust. Therefore, pressure is a scalar quantity. When the force applied on the surface is not perpendicular to the surface, its magnitude of the component of the force perpendicular to the surface is considered.