A number of children are playing with two sleds on a smooth, level, snow covered playground. After some thought and experimentation, they decide that the configuration shown below will give them the fastest ride if the two strongest children (Betty and Carl) pull the sleds. Carl pulls with a force of FC = 235 N at an angle of 20.0° with respect to the forward motion, and Betty pulls with a force of FB = 200 N at an angle of θB = 23.70°, also with respect to the forward motion. David sits backwards on the trailing sled and drags his feet. The sled combination moves forward with a constant velocity across the snow for a distance of 20.0 m, as shown in the diagram below. Determine the following.