Answer:
3.2 kg
Step-by-step explanation:
From Newton's second law of motion:
, where F is the force needed to give a mass m an acceleration a. Here, we have F = 16N and a = 5 m/s². Substituting those values in to our formula gives us 16N = (5 m/s²)m, and solving for mass gives us 16/5 = 3.2 N/(m/s²).
Since a Newton is defined with the units kg·(m/s²), the units of acceleration in the numerator an denominator cancel, leaving us just with units of mass, so our mass is exactly 3.2 kg.