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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
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
The can be found elsewhere and as follows:
<span>A. of magnetic effects.
B. the ball tries to pull the rod’s electrons over to it.
C. the rod polarizes the metal.
D. the rod and the ball have opposite charges.
</span><span>
I believe the correct answer is option C. If a negatively charged rod is held near a neutral metal ball, the ball is attracted to the rod. this happens because </span>the rod polarizes the metal. Hope this answers the question.
Explanation:
sinces : Momentum = velocity × mass
then : 30 = 10 × m and m = 30 ÷ 10 = 3 kg