Answer: 2.5N
Explanation: To determine the magnitude of the force of friction acting on the mass, we need to use Newton's second law of motion. According to the law, the net force acting on an object is equal to the product of its mass and acceleration.
In this case, the net force is the force applied minus the force of friction. The force applied is 10 N, the mass is 5 kg, and the acceleration is 1.5 m/s^2.
Using the equation F_net = ma, we can rearrange it to solve for the force of friction.
F_friction = F_applied - F_net
F_friction = 10 N - (5 kg * 1.5 m/s^2)
F_friction = 10 N - 7.5 N
F_friction = 2.5 N
Therefore, the magnitude of the force of friction acting on the mass is 2.5 N.