Final answer:
The total force exerted on the log by two tractors pulling at an 18.0° angle (each at 9.0° to the log) is found by summing the parallel components of the force from each tractor, resulting in a total force of 1580 N.
Step-by-step explanation:
To determine the total force exerted on the 1000 kg log by two tractors pulling at an angle of 18.0°, we can use components of forces along parallel and perpendicular to the direction of the log.
Since the angle between the chains and the log is 9.0° for each tractor, the force in the direction parallel to the log (F_par) for each tractor is:
F_par = F × cos(θ) = 800 N × cos(9.0°) = 800 N × 0.9877 ≈ 790 N
The total force parallel to the log is the sum of the forces applied by both tractors:
Total F_par = F_par (tractor 1) + F_par (tractor 2) = 790 N + 790 N = 1580 N
Therefore, the total force exerted by the two tractors is 1580 N, which corresponds to option C.