Answer:
Explanation:
Notation
represent the tensile strength for the Kevlar 49 fibers
represent the tensile strength for the epoxy resin
79% by volume is made of Kevlar 49 fibers
The rest 100-79=21% is made of epoxy resin
Tensile strength is a "measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks". Can be defined as "the maximum amount of tensile stress that it can take before failure".
For this case we need to use a basis of calculus since we don't know the total volume but we can assume a reference value on order to make the calculations.
If we assume a total volume of 
we can do the follwoing balance:
We can replace the values given:
So then the strength of the composite material is :
We can use the formula of motion in physics (2nd law od newton) in this problem:
x direction: Fsin ∅ = ma
y direction: Fcos ∅ -mg = 0
∅ is equal to sin ∅ / cos ∅ or x/y
tan ∅ = ma / mg = a /g
Applying acceleration formula:
v = vo + at ; 28 = 0 + 6a ; a = 4.67 m/s^2
∅ = tan-1 (a/g) = tan-1 (4.67/9.81) = <span>25.4 degrees.</span>
Q = magnitude of charge on each of the two point charge = 3.60 mC = 3.60 x 10⁻³ C
r = distance between the two point charges = 9.3 cm = 0.093 m
k = constant = 9 x 10⁹ Nm²/C²
F = magnitude of the force between the two point charges = ?
according to coulomb's law , force between two charges is given as
F = k Q²/r²
inserting the values
F = (9 x 10⁹) (3.60 x 10⁻³)²/(0.093)²
F = 1.35 x 10⁷ N
<u>Answer:</u>
Option (a)
<u>Explanation :</u>
A stage hand starts sliding a large piece of stage scenery originally at rest by pulling it horizontally with a force of 176 N.
Hence Force applied 
Force on piece of scenery 
µk = 
= 
=
=0.36
coefficient of static friction is 0.36
Answer:
n = 10 beats
Explanation:
Given:
- Frequency of note f1 = 151 Hz
- Frequency of note f2 = 155 Hz
- The total time they ring t = 2.5 s
Find:
How many beats are heard
Solution:
- The frequency of beat (fb) is the difference between the two frequencies of notes as follows:
fb = f2 - f1
fb = 155 - 151
fb = 4 Hz
- The number of beats per second is also called beat frequency:
n = fb*t
n = 4*2.5
n = 10 beats
