The frictional force acting on the load is equal and opposite to the horizontal component of the force applied in the rope, which is 1060.65N, calculated using trigonometry and the fact that the load moves at a constant velocity.
To find the frictional force acting on a load that is being pulled with a force of 1500N at a 45° angle, we must consider the components of this force. Since we're looking at a horizontal floor, we only need to be concerned with the horizontal component of the force. The horizontal (and vertical) component of the force can be found by multiplying the total force by the cosine (or sine) of the angle. Using trigonometry:
F_horizontal = F_total × cos(θ)
F_horizontal = 1500N × cos(45°)
F_horizontal = 1500N × 0.7071 (since cos(45°) is approximately 0.7071)
F_horizontal = 1060.65N
This horizontal component of the force is the one that works against friction. Since the load is moving at a constant speed, the net force must be zero, so the frictional force must be equal and opposite to the horizontal component of the force applied in the rope, which is 1060.65N.