Final answer:
To find the mass of the box, you can use the work-energy principle. The work done on an object is equal to the change in its kinetic energy. In this case, the work done on the box is 350 J and the box is being pulled at a steady speed, so its kinetic energy remains constant.
Step-by-step explanation:
To find the mass of the box, we can use the work-energy principle. The work done on an object is equal to the change in its kinetic energy. In this case, the work done on the box is 350 J and the box is being pulled at a steady speed, so its kinetic energy remains constant. Therefore, the work done is equal to zero.
The work done on an object is given by the formula:
Work = Force x Distance x cos(theta)
Since the work done is zero, we can rearrange the formula to find the force:
Force = -Work / (Distance x cos(theta))
Given that the distance is 4.0 m and the force is the weight of the box, we can calculate the mass of the box using the formula:
Weight = mass x gravity
where gravity is the acceleration due to gravity. Rearranging the formula gives:
mass = weight / gravity