3.A sled is being pulled across a barn floor by a force of +320 N. The coefficient of sliding friction between sled and the floor is 0.45. The mass of the sled is 65 kg. A) What does the sled weigh? B) What is the force of friction acting on the sled? C) What is the net force acting on the sled? D) What is the sled's acceleration? 4. A crate is being pulled by a rope which is horizontal to the floor. The crate's mass is 45.0 kg and it is currently accelerating at +3.50 m/s2. The coefficient between the floor and the crate is 0.300. A) What is the amount of the net force acting on the crate? B) What is the tension on the rope? (Hint: What is the applied force, and what is pulling the crate?) C) If the crate started from rest, how fast will the crate be going once it is moved 6.00 m? D) How much force is needed on the rope to keep the crate moving at the velocity found in part C? 5. A large model rocket has a mass of 30.0 kg. It's engine can generate a thrust of 750.0 N. A) What is the net force acting on the rocket when its engine is fired? B) What is the acceleration of the rocket when its engine is burning? C) If the engine burns for 20.0 seconds, how far will the rocket travel under that acceleration? 6. A sled is being pulled across a floor. The sled's mass is 75.0 kg and the coefficient of sliding friction is 0.250. If the sled is pulled by a force of 250.0 N, what is the acceleration of the sled?