Final answer:
When both the mass and the net force acting on a sliding block are tripled, the acceleration remains unchanged due to the proportional relationship between force, mass, and acceleration.
Step-by-step explanation:
If the mass of a sliding block is tripled while the net force is also tripled, the resulting acceleration will remain the same as the original acceleration. This is because acceleration (a) is given by Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force (Fnet) acting upon it and inversely proportional to its mass (m), as shown in the equation a = Fnet/m. Hence, if both the mass and the force are tripled, they cancel each other out, resulting in the same value for acceleration.