Jumping off a raft

A raft of mass 180kg carries two swimmers of 50 kg and 80 kg. Raft initially at rest but swimmers dive off opposite ends each at 3 m/s. With what velocity and in what direction does to raft start to move?

Impulse concepts

Discuss the following in terms of impulse and momentum: Why are padded dashboards safer in cars? Why are nylon ropes, which stretch under stress, favored by mountainclimbers? Why is it preferrred that railroad cars be loosely coupled with slack between cars?

Momentum concepts

Why is it difficult for a fire-fighter to hold a hose that ejects large amounts of water at high speed? If an 18-wheeler hit Geo (small car) at equal speeds in a head-on collision: Which vehicle will experience the greatest ... force of impact? change in momentum? acceleration? A billiard ball will stop when it collides head-on with another ball at rest. But will not stop if the collision is not exactly head-on but at an angle. Explain why in term of momentum.

Need experiment to demonstrate how fluids move from areas of high pressure to low pressure

I need an experiment to demonstrate how fluids move from areas of high pressure to low pressure. My teacher has given examples, but I can't use any of hers. I've been working for days and am stuck and under the gun.

How to implode a 44 gallon drum

I am doing a low budget film shoot in australia that requires ( as a comedy skit) a 44 gallon drum to imlode. I need to find a safe way to do this. There are no requirements for any actors to be close to the drum. I need to know how to achieve this effect, cheaply and safely. anyone out there with a solution?