Here's a quick science quiz to help you know if you understand basic scientific principles. I'll use some questions from a similar quiz by Mike Wong, along with some from this quiz, along with others.
Questions
Is it possible to do 1KJ of work without expending 1KJ of energy?
Someone tells you they're created a perpetual motion machine. How should you respond?
Which has a longer wavelength, microwaves or infrared?
Why is the air inside of an oven less dangerous to touch than the insides of the metal walls of said oven?
Why does metal feel so cold at room temperature?
What does the ozone do?
A punch can have much more momentum than a bullet. Why, then, can't we punch through metal?
What is the kinetic energy of a car with a mass of 1200 kg traveling at 10 m/s?
If Superman tried to push a 500-lb safe down a hallway, could he do it?
Do Star Trek phasers vaporize people?
Answers
Nope. The First Law of Thermodynamics states that the amount of energy in a closed system can never change. (Note that much energy can be wasted as it turns into heat per the Second Law of Thermodynamics.)
How I'd probably respond: "No, you haven't. The First Law of Thermodynamics rules out any such thing. The whole point of a perpetual motion device is that it's a closed system whose energy level changes." If someone actually believes in perpetual motion despite this explanation, they are either woefully ignorant or woefully moronic.
Microwaves.
Metal is better at heat transfer. While the air and the metal are the same or nearly the same temperature, metal can pump energy into your hand much faster.
Metal is also great at sucking heat out of things. It's a great conductor of heat.
It stops ultraviolet light from entering the lower atmosphere and giving us cancer.
The bullet is both more pointed and much harder. It focuses the force into a smaller area, and it deforms less compared to the target. (Also, a bullet impacts over a much shorter timeframe, increasing the maximum pressure at the tip.)
The formula for KE is 1/2mv^2. 0.5 times 1200 times 10^2 equals 60000 joules. (If you prefer to have your math done for you, or just want to check your work, this calculator is very helpful.)
No. He would slide, not the safe. See Life of Fred: Physics for a detailed explanation.
No. If they did, the room would be filled with hot water vapor, which would scald anyone else in the room. They most likely use an unknown chain reaction to turn matter into neutrinos.
If you are over 14 and got less than 5 right, I think you should rethink your life. Otherwise, don't worry too much.
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