Several incline angles are typically used; yet, the force is always applied parallel to the incline. The displacement of the cart is also parallel to the incline. Since F and d are in the same direction, the angle theta in the work equation is 0 degrees. read more
The most complicated part of the work equation and work calculations is the meaning of the angle theta in the above equation. The angle is not just any stated angle in the problem; it is the angle between the F and the d vectors. In solving work problems, one must always be aware of this definition - theta is the angle between the force and the displacement which it causes. read more
Nevertheless, most students experienced the strong temptation to measure the angle of incline and use it in the equation. Don't forget: the angle in the equation is not just any 'ole angle. It is defined as the angle between the force and the displacement vector. read more
The work formula includes the cosine of the angle between the force and distance for this reason. If the force and movement are in the same direction, than the angle is equal to 0 radians (or 0°). The cosine of zero is: cos0 = 1. The units of work are Joules (J), where 1 J = 1 N∙m = 1 kg∙m 2 /s 2. read more