To what temperature would you have to heat a brass rod for it to be 1.8 % longer than it is at 30 ∘c?

1 answer:

3 0

In physics, certain metals elongate when it is heated. This is a consequence of the expansion of the molecules present in a metal tube, for example. This elongation is described by the equation:

ΔL = L0*α*ΔT, where

ΔL is the elongation. In other words, this is the difference between the original length and the elongated length.
L0 is the original leng
α is the coefficient of linear expansion. This is an empirical data for specific kind of materials. For brass, α = 18.9 x 10^6/°C
ΔT is the change in temperature

Rearranging the equation,

ΔL/L0 = α*ΔT, where ΔL/L0 is the percentage of length expansion which is equal to 0.018 (1.8^%)

0.018 = (18.9 x 10^-6)(T-30)
T = 982.4°C

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3 years ago

A crude approximation for the x component of velocity in an incompressible laminar boundary layer is a linear variation from u =

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Answer:

2.5 * 10^-3

Explanation:

solution:

The simplest solution is obtained if we assume that this is a two-dimensional steady flow, since in that case there are no dependencies upon the z coordinate or time t. Also, we will assume that there are no additional arbitrary purely x dependent functions f (x) in the velocity component v. The continuity equation for a two-dimensional in compressible flow states:

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u=U*y/cx^1/2

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v=∫δv/δy(dy)=U*y/4cx^1/2

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v/U=u*y/4*U*x

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