Answer:
697 m
Explanation:
From the question above,
Note: Alice hears the splash of the rock in the well through the help of echo.
Applying,
v = 2x/t........................ Equation 1
Where v = speed of sound, x = depth of the well, t = time.
make x the subject of the formula in equation 1
x = vt/2................... Equation 2.
Given: v = 340 m/s, t = 4.1 s
Substitute these values into equation 2
x = 340(4.1)/2
x = 697 m.
Waves carry energy from one place to another. Because waves carry energy, some waves are used for communication, eg radio and television waves and mobile telephone signals. ... Some types of waves need to be transmitted through matter, either a solid, liquid or a gas. For example, water waves have to travel in water.
There is too much information given, it's hard to understand exactly which variables are important in this problem.
Answer:
Option C is correct.
Modulus of elasticity of the composite perpendicular to the fibers = (12 × 10⁶) psi
Explanation:
For combination of materials, the properties (especially physical properties) of the resulting composite is a sum of the fractional contribution of each material thay makes up the composite.
In this composite,
The fibres = 20 vol%
Aluminium = 80 vol%
Modulus of elasticity of the composite
= [0.2 × E(fibres)] + [0.8 × E(Al)]
Modulus of elasticity of the fibers = E(fibres) = (55 × 10⁶) psi. =
Modulus of elasticity of aluminum = E(Al) = (10 × 10⁶) psi.
But modulus of elasticity of the composite perpendicular to the fibers is given in the expression.
[1 ÷ E(perpendicular)]
= [0.2 ÷ E(fibres)] + [0.8 ÷ E(Al)]
[1 ÷ E(perpendicular)]
= [0.2 ÷ (55 × 10⁶)] + [0.8 ÷ (10 × 10⁶)]
= (3.636 × 10⁻⁹) + (8.00 × 10⁻⁸)
= (8.3636 × 10⁻⁸)
E(perpendicular) = 1 ÷ (8.3636 × 10⁻⁸)
= 11,961,722.5 psi = (11.96 × 10⁶) psi
= (12 × 10⁶) psi
Hope this Helps!!!
