An object of mass m moving in a certain direction has a kinetic ...

[james]

An object of mass m moving in a certain direction has a kinetic energy of 4.0 J. It hits a wall and comes back with half its original kinetic energy. If the speed of the object on return is 2.0 m/s, what is the mass of the object?
 
  A) 2.0 kg
  B) 2.8 kg
  C) 3.8 kg
  D) 1.0 kg
  E) 4.0 kg

Question 2

In fluid flow, the character of the flow can be determined by the Reynolds number, Re, which is a dimensionless quantity that can be expressed in terms of the speed v of the fluid, the density  (mass per unit volume) of the fluid, the viscosity
 
  of the fluid, and a length D which is characteristic to the flow. Re can be expressed in the form Re = kvabDc, where k, a, b, and c are dimensionless constants. What must be the values of b, c, and d? The dimensions of viscosity are M/LT. A) b = 1, c = -1, d = 1
  B) b = 1, c = -1, d = -1
  C) b = -1, c = 1, d = 1
  D) b = -1, c = 1, d = -1
  E) b = -1, c = -1, d = 1

[debra928]

Answer to Question 1

D

Answer to Question 2

C

[james]

Thanks

[debra928]

Welcome