To support the student's claim that Box 1 must have a smaller mass than Box 2, we can use Newton's second law of motion, which states that \( F = ma \), where \( F \) is the force applied, \( m \) is the mass, and \( a \) is the acceleration.
Since both boxes are subjected to the same force of 20 newtons, we can analyze the relationship between mass and acceleration:
-
For Box 1:
- Force (F) = 20 N
- Acceleration (a) = 5 m/s²
- Using \( F = ma \), we can rearrange it to find mass: \( m = \frac{F}{a} = \frac{20 \text{ N}}{5 \text{ m/s}²} = 4 \text{ kg} \).
-
For Box 2:
- Force (F) = 20 N
- Acceleration (a) = 2 m/s²
- Again using \( m = \frac{F}{a} = \frac{20 \text{ N}}{2 \text{ m/s}²} = 10 \text{ kg} \).
From this analysis, we can see that Box 1 has a mass of 4 kg while Box 2 has a mass of 10 kg. Therefore, the argument that best supports the student's claim is that since both boxes are exerting the same force but Box 1 is accelerating more (5 m/s² compared to 2 m/s² for Box 2), Box 1 must indeed have a smaller mass than Box 2, because the same force results in a higher acceleration for a lower mass according to Newton's second law.