Final answer:
The box has gained potential energy. Potential energy is the energy stored in an object when it is positioned above the ground, calculated as the product of its mass, gravity, and height.
Step-by-step explanation:
A woman uses 70 J of energy to lift a box. Since the box was lifted above the ground, the box has potential energy.
When a woman uses 70 J of energy to lift a box above the ground, the box gains potential energy. Potential energy is the energy that an object possesses due to its position or configuration. It is given by the equation P.E. = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height above the ground. In this case, the box has gained potential energy equal to 70 J.
The concept here is that when work is done against gravity to lift an object, the energy is converted into potential energy. This potential energy is equal to the product of the object's mass (m), the acceleration due to gravity (g), and the height (h) the object is lifted. This is often expressed as the equation Ep = mgh, where Ep is the potential energy. In the case of the example given, lifting a box with a force equivalent to 70 J of energy means that the box now has 70 J of potential energy stored in it due to its new position above the ground.