A block with mass m is being pushed by a constant force F that makes an angle of 0 with the horizontal as shown below. The block is moving with constant velocity on a level surface. The coefficient of kinetic friction between the block and the surface is MK. Which one of the following equations is correct for the magnitude of F? F umg O T' = cos O + 4, sin 0 O F= umg cos 0 - My sin 0 O 2 cos 0 + u, sin 0 OF- cos 0 + 2mg sin 0 OF- MyIng tan 8