1)- A person lifts a mass of 20.0 kg vertically upwards at a constant speed of 0.200 m/s through a distance of 0.800 m. What is the work done by the person? A) 156.8 J B) 3.20 J C) 16.0 J D) None of the other choices is correct. I choosed the answer B. I used the law : W = F x D = (20 x 0.2) x 0.8 = 3.2 Am i correct? ________________________________________________________ 2)- A truck is towing a car whose mass is one quarter that of the truck. The force exerted by the truck on the car is 6000 N. The force exerted by the car on the truck is A) 6000 N. B) 24000 N. C) 3000 N. D) 1500 N. I choosed the answer D, because the the force exerted by the truck on the car is 6000 N, and the car's mass is one quarter that of the truck, so 6000/4 = 1500 N. Am i correct? _________________________________________________________ And for this question.. i only need to know the law.. A 40.0-kg crate is being lowered by means of a rope. Its downward acceleration is 2.00 m/(s)2 . What is the force exerted by the rope on the crate? A) 312 N. B) 40.0 N. C) 472 N. D) 232 N.