In some wind tunnels, the test-section wall is porous or perforated; fluid is sucked out to provide a thin viscous boundary layer. the wall of the test section is 4 m long and contains 800 holes of 6-mm diameter per square meter of area. the suction velocity out each hole is vs = 10 m/s, and the test section entrance velocity is v1 = 45 m/s. assuming incompressible flow of air at 20c and 1 atm, compute (a) v0, (b) the total wall suction volume flow, (c) v2, and (d) vf.

Aman tries to push a box of mass 4 kg with a force of 5 n but the box remains stationary if the coefficient of static friction is 0.45, what is the value of the maximum force of friction?

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

A1,700kg car is being used to give a 1,400kg car a push start by exerting a force of 140n the impulse on the smaller car during the 30.0s of contact is +670kg*m/s. what is the impulse of the smaller car on the larger car? -814 kg*m/s 0kg *m/s -670kg*m/s -550kg*m/s