Afinned wall is constructed of aluminum. the fins are circular- rod/pin. the wall is maintained at a constant temperature of 100 oc and the fins are exposed to a convection environment at 20 oc. the assembly will be cast from the aluminum material and must dissipate 50 w of heat under the conditions noted and using minimum weight of aluminum. assuming a square array, determine suitable combinations of number of fins, fin spacing and fin dimension to accomplish this cooling for film heat transfer coefficients of 8 w/m2 oc and 20 w/m2 oc. assume the wall to be 2 mm thick and a uniform value of h for both the fin and wall surface.

    m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| =  √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| =  √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| =  14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s

The fertilized egg  begins to develop into a hollow ball of cells called the blastocyst.