General Science Part IV Trivia Quiz

Answer: No

This might seem odd, but the average temperature in the room will increase. On the back of your refrigerator will be a heat exhaust. It takes a lot of energy to cool down something. It takes you more energy to cool something down with 10 degrees than to heat something up with 10 degrees.

Therefore there will be more heat generated on the back of the refrigerator than the coolness in the refrigerator, hence the overall average temperature of the room will increase. You could drill a hole in the wall and make sure the heat exchanger is hanging outside the room, allowing you to cool down your room (and heating up the next one of course).

Answer: get hit by an old tennis ball

There is a big difference in the impact you'll feel depending on the condition of the ball. A new ball is very hard, and will cause an almost elastic collision. Your skin feels the impact of the collision, but must also deliver the force for the bounce back of the ball.

This according the Third Law of Newton: action equals reaction. So your skin will feel two times the impact. When the ball was already used, it became a bit soft (weak) and therefore the collision will be far less elastic. A lot of the energy involved will be dissipated (transformed) into heat, and therefore the remaining impact on your skin will be less.

Answer: the massive wooden cylinder

This has to do with the rotational inertia moment. The iron tube has a very high rotation moment because the mass is situated at a big distance from the rotation axis of the cylinder. The wooden cylinder has the mass more equally divided over the area, the moment will be much less. To accelerate mass you need energy.

The lower the moment of inertia, the quicker the cylinder will start moving. Therefore the wooden cylinder will be down first. The same principle is used in iceskating when performing a pirouette: when you stretch your arms, the rotation will become slower (because you increase your moment of inertion).

Answer: almost 0.16 meters

The circumference of a circle is always 2 x Pi x Radius. When R is the radius of the moon and L is the lenght of the rope, the calculation goes as follows: 2 x Pi x R = L and 2 x Pi x (R-r) = L-1.
When I substract the second equation from the first one, I get 2 x Pi x r = 1. Therefore r = 1 / (2 x Pi) or r = 1/6.28 and r = 0.1592 . Amazing, not?

Answer: The first time hot air will enter the freezer. When the door is closed, the air inside will contract and you get a partial vacuum inside.

The available space (volume) in the freezing compartment is constant. Air is a gas, the pressure of a gas is dependent on the temperature. The higher the temperature, the more the molecules will be moving around, hence the more collisions you get, hence the higher the pressure will be. So, if you cool down the air, the pressure will decrease inside the freezing compartment.

Therefore the pressure outside the door will be higher than on the inside, making it harder to open the door. Hope you enjoyed the quiz!