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 collid ...continues

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?

Physics Problems

Please see the attached file for full problem description.

Potential Difference, Current and Resistance

1. In a particular television tube, the beam current is 60.0 MuA. How long does it take for 3.75 x 10^14 electrons to strike the screen? 2. A stereo with a resistance of 65 ohms is connected across a potential difference of 120 V. What is the current in this device? 3. The current in a microwave oven is 6.25 A. If the ...continues

resistance

1. An ammeter registers 2.5 A of current in a wire that is connected to a 9.0 V battery. What is the wire's resistance? 2. A small electronic device is rated at 0.25 W when connected to 120 V. What is the resistance of this device? Please include the answers, formulas used and work done. Thank you!

Geometrical Optics

A small insect is placed 5.41cm from a +6.59cm focal length lens. Calculate the position of the image. Calculate the angular magnification.

optics

Reading glasses of what power (D) are needed for a person whose near point is 121cm, so that he can read a computer screen at 48.8cm? Assume a lens eye distance of 1.83cm.

short answer

Which kind of spherical mirror, concave or convex, can be used to start a fire with sunlight? and for the best results, how far from the mirror should the paper to be ignited be placed? Explain your answers.