Question

Determine the pressure difference that is required to fill a cell phone housing in one tenth of a second. Model the shape as a flat plate that is injected over its full width, assume Newtonian behavior, and use a viscosity μ = 36 Pa.s.

Answer 1

Answer:

P1 - P2 = 276 x 10^5 pa

Explanation:

Here we are provided with the following data:

Viscosity (µ) = 36 pa.s

Thickness (t) = 1.5 mm

Length (L) = 120 mm

time (s) = 1/10 = 0.1 sec

velocity = v= L/s = 120/0.1

v = 1200 mm/sec

Now we will calculate the pressure difference using the formula of flat plate.

P1-P2=  12(μ*v*L)/t^2

here  P1 and P2 are the pressures,

Substituting values in the formula above

P1 - P2 = (12*36*1200*120)/(1.5^2)

P1 - P2 = 276 x 10^5 pa