Answer:
A) B = 24 ft
B) H = 24.08 ft
C) M.A = 12.04
D) P = 13.7 lb
Explanation:
A)
Minimum allowable length of base of ramp can be found as follows:
Slope = H/B
where,
Slope = 1/12
H = Height of Ramp = 2 ft
B = Length of Base of Ramp = ?
Therefore,
1/12 = 2 ft/B
B = 2 ft * 12
<u>B = 24 ft</u>
B)
The length of the slope of ramp can be found by using pythagora's theorem:
L = √H² + B²
where,
H = Perpendicular = height = 2 ft
B = Base = Length of Base of Ramp = 24 ft
L = Hypotenuse = Length of Slope of Ramp = ?
Therefore,
H = √[(2 ft)² + (24 ft)²]
<u>H = 24.08 ft</u>
D)
The mechanical advantage of an inclined plane is given by the following formula:
M.A = L/H
M.A = 24.08 ft/2 ft
<u>M.A = 12.04</u>
D)
Another general formula for Mechanical Advantage is:
M.A = W/P
where,
W = Ideal Load = 165 lb
P = Ideal Effort Force = ?
Therefore,
12.04 = 165 lb/P
P = 165 lb/12.04
<u>P = 13.7 lb</u>
Answer:
Explained
Explanation:
This happens because the water cancels the focusing effect of our eye lens. A drop of water makes a lens because of the different refractive indices of water and air.
When we are underwater with naked eyes, the front part of our eye lens does not have different refractive indices anymore… both the inside lens and outside lens are essentially water ( lens inside our eyes are water only surrounded by a membrane)… hence, that part of the lens does not focus the light anymore. And thus, your eyes don’t work well anymore. (It can only partly correct for this, by bending the lens more)
When we put swimming goggles on, we remove the water and again have air in front of our eye lenses, and they work normally now. Obviously, we have created an extra interface between water and air in front of our swimming goggles. However, this surface(the goggle) is flat. And thus it does not function as a lens but only as a window.
Answer:
It reveals that light is a wave
Explanation:
Diffraction is the property of a wave in which there is a bending of the wave about the corners of an obstacle or aperture into the geometrical shadow of the obstacle or aperture.
This simply implies that a wave bends or spreads out when it passes through openings. Since the light diffracts through small slits and diffraction has been shown to occur in water waves and sound waves, this property of diffraction can only be characteristic of a wave and thus, this evidence reveals that light is a wave.
Lydia is an example of an optimist. Optimists always look at the positive side of a particular situation. They believe in a positive result. Optimist always see "the bright side" as opposed to the pessimist. The word optimism comes from latin word "optimum" which means "the best".