On arrival at a vehicle collision, you observe a small fire in the engine compartment. A bystander is attempting to smother the fire with a jacket as you approach with an A-B-C extinguisher from your ambulance. Which of the following is the best method of extinguishing the fire? a. Sweep the nozzle of the extinguisher left and right using short bursts until you are out of extinguishing agent.
b. Aim at the base of the fire and use short bursts until the fire is out.
c. Close the hood to contain the fire within the engine compartment.
d. Aim the nozzle to the side of the fire and, with a sweeping motion, push the fire at its base

Laboratory experiments, observational field studies, and model-building are all examples of different forms of scientific investigations.  in what way do laboratory experiments primarily differ from other forms of scientific investigations?   a.  a laboratory experiment is the only accepted form of investigation within the scientific community.  b.  studies about how things behave in nature or studies involving very large objects are best answered through laboratory experiments.  c.  laboratory experiments involve the identification and control of variables.  d.  data can only be generated through laboratory experiments, not other forms of investigation.

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

What are similarities and differences between refraction, reflection, diffraction and absorption?