The force applied can be calculated by multiplying the mass of the object by its acceleration. This is known as Newton's second law of motion, which states that force equals mass times acceleration (F=ma).
The amount of frictional force opposing an object's motion depends on the nature of the surfaces in contact, the normal force (the force exerted by the surface on the object), and the coefficient of friction (a measure of the roughness of the surfaces).
The constant frictional force opposing an object's motion can be calculated by multiplying the coefficient of friction by the normal force. This is known as the frictional force equation (Ff=μN).
Static friction is the force that prevents an object from moving when it is at rest, while kinetic friction is the force that opposes the movement of an object that is already in motion.
The angle of the surface can affect the force applied and frictional force by changing the normal force. The steeper the angle, the greater the normal force and therefore, the greater the frictional force. If the surface is horizontal, the normal force is equal to the force applied and there is no change in the frictional force.