By definition, a cube is a three-dimensional figure that have equal dimensions for all its sides. It comprises of two square bases, one on top and one on the bottom. The face sides are also squares. Therefore, the volume of a cube is equal to s³, where s is the measure of the side's length. To compare the change, let us assume values. First, suppose s=1. Then, we denote this volume as V₁.
V₁ = (1)³ = 1
Next, taking the double, s=2. The volume for this is denoted as V₂.
V₂ = (2)³ = 8
Taking the ratio of V₂ to V₁:
V₂/V₁ = 8
That means the scale factor is 8. When the side dimensions is doubled, the volume of the cube increases 8 times as great as the original volume.
Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
Answer:
151.9 N
Explanation:
Force = mass x acceleration
Acceleration due to gravity is 9.8 m/s^2 (you should memorize this number).
F = ma
F = (15.5)(9.8)
F = 151.9
Answer:
54.3N
Explanation:
The normal force is perpendicular to the slope, so:
Normal Force = cos(37.2)(9.8*65).......507.39N
F(friction)=mu*F(normal)
F(friction)=(0.107)(507.39)
F(friction)=54.3N
A compound. For example, hydrogen and oxygen atoms form water.
