Final answer:
The work done by gravity and normal force on the 10 kg block is 0 J, friction does -98 J, and the applied force does 2598 J of work. The net work done on the block is 2500 J.
Step-by-step explanation:
When a 10 kg block is pulled across a rough floor with an applied force of 150 N at 30° above horizontal, the work done by each force can be calculated as follows:
- Work done by gravity (Wg) is 0 because gravity acts vertically while the displacement is horizontal.
- Work done by the normal force (Wn) is also 0, for the same reason as gravity—it acts perpendicular to the displacement.
- To calculate the work done by friction (Wf), we first need to find the frictional force which is the coefficient of kinetic friction (μ_k) multiplied by the normal force (N). Assuming N equals mg because the block is only moving horizontally, Wf = μ_k * N * d = 0.05 * 10 kg * 9.8 m/s² * 20 m = -98 J (negative because it acts opposite to the displacement).
- The work done by the applied force (Wa) is cos(θ) * F * d = cos(30°) * 150 N * 20 m = 2598 J.
To find the net work done on the block, we would add up all the individual works: W_net = Wg + Wn + Wf + Wa = 0 + 0 - 98 J + 2598 J = 2500 J.