A person using a lever applies to lift a 20-kilogram box. They apply the force over a distance of 4 meters to lift the box a distance of 2 meters. How much work is done?
m * g * h ... 20 kg * 9.81 m/s^2 * 2 m = ? Joules
To find the work done, you need to use the formula:
Work = Force × Distance
In this case, the force is the effort applied using the lever, and the distance is the distance over which this force is applied.
Given that the person applied the force over a distance of 4 meters and lifted the box a distance of 2 meters, you would use these values to calculate the work done.
Let's assume that the force applied by the person is F.
Now, we can equate the work done to the force multiplied by the distance:
Work = F × Distance
The distance over which the force is applied is 4 meters, and the force needed to lift a 20-kilogram box against gravity is the weight of the object.
The weight can be calculated using the formula:
Weight = Mass × Gravitational Acceleration
In this case, the mass is 20 kilograms, and the gravitational acceleration on Earth is approximately 9.8 meters per second squared.
Weight = 20 kg × 9.8 m/s^2
Now, we can substitute the value of the weight into the equation for work:
Work = Weight × Distance
Work = (20 kg × 9.8 m/s^2) × 4 m
Work = 784 kg·m^2/s^2
To simplify the unit, we can convert "kg·m^2/s^2" to joules (J), which is the standard unit for work:
1 J = 1 kg·m^2/s^2
Therefore,
Work = 784 J
So, the work done by the person using a lever to lift the 20-kilogram box is 784 joules.