Sally does 11,400J of work to drag a wooden crate 25m across a floor with a constant speed. The rope attached to the crate makes an angle of 48 with the floor.
To calculate the work done by Sally, we need to find the horizontal component of the force she applied to drag the crate.
The work done is given by the formula:
Work = Force x Distance x cos(theta)
where theta is the angle between the force and the direction of motion.
Given that work done is 11,400J, distance is 25m, and theta is 48 degrees, we can rearrange the formula to find the force:
Force = Work / (Distance x cos(theta))
Force = 11,400J / (25m x cos(48))
Force = 11,400J / (25m x 0.6691)
Force = 11,400J / 16.7275
Force ≈ 680.12N
Therefore, Sally applied a force of approximately 680.12N to drag the wooden crate across the floor.