(50kg)(4m/s)+(75kg)(-1m/s)=Pfinal What is the answer

You carry a 7.0-kg bag of groceries 1.2 m above the ground at constant speed across a 2.7m room. how much work do you do on the bag in the process? (a) 157j (b) 0.00j (c) 185j (d) 82j

Part 1: a magnetic levitation or maglev train rides rails without touching them. explain how this works using your data. include the appropriate magnet drawing in your answer. part 2: two objects are near a bar magnet. one is about 1 cm away, while the other is 6 cm away. compare and contrast the magnetic force that affects each object. use your data to answer the question

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant