-
Air (ρ = 1.2 kg/m3 and kinematic viscosity, υ = 2 × 10-5 m2/s) with a velocity of 2 m/s flows over the top surface of a flat plate of length 2.5 m. If the average value of friction coefficient is
Cf = 1.328 √Rex
the total drag force (in N) per unit width of the plate is _________.
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- 0.1159
- 0.0259
- 0.0157
- 0.0159
Correct Option: D
| Cf = | ||
| √Rex |
| Rex = | = | ||
| μ | υ |
v = 2m/s
1 = 2.5m
υ = 2 × 10–5 m²/s
F = 1/2 CfρAυ²
A = 2.5 × 1
On substituting we get
F = 0.0159N
