Final answer:
To determine a crate's mass from its acceleration of 4 m/s², the force applied to the crate would be required. Without that information, it is impossible to calculate the crate's mass using Newton's second law (F = ma).
Step-by-step explanation:
The calculation of a crate's mass based on a given acceleration and force can be derived using Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma). If we rearrange this equation to solve for mass (m), we get m = F/a. In this scenario, we are not provided with the exact force acting on the crate; we only have the acceleration, which is 4 m/s². Without knowing the actual force that corresponds to this acceleration for the crate, we are unable to calculate the crate's mass.