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In physics, force is a push or pull upon an object resulting from the object's interaction with another object. When there's an interaction between two objects, there is a force upon each of the objects. Whenever the interaction ceases, the two objects no longer experience the force. We use Newtons (N) as the unit of force, named after Sir Isaac Newton.
When lifting weights, the weight lifter needs to apply a force to counteract the force of gravity. In our exercise, the force applied is 350 Newtons. These 350 Newtons are used to stabilize the weights over the weight lifter's head at constant speed. This means the force applied balances out the gravitational force acting downwards on the weights, allowing for steady and safe elevation without acceleration.
Some key points to remember about force:

• It is a vector quantity, which means it has both magnitude and direction.
• The greater the force applied, the greater the potential for movement or deformation of the object.
• Force needs to be applied over a distance for work to be done, which brings us to the concept of work in physics.

Distance, in physics, is the measure of how much ground has been covered during motion. It is a scalar quantity, meaning it only has magnitude and no direction. In our problem, the weight lifter moves the weights a vertical distance of 2.00 meters. This is the displacement the weights experience away from the starting point on the ground level.
When considering work, the distance over which the force is applied is crucial. Without movement across a distance, no work is done, even if a force is applied. For instance:

• If the weight lifter simply holds the weights steady overhead without moving them, technically no work is done since there's no distance covered in the direction of the force.
• The direction of the distance moved matters; for work to be calculated, the movement needs to be in the same direction as the applied force.
• Distance is usually measured in meters (m), consistent with the metric system you'll use for all physics calculations.

In physics, work is the measure of energy transfer that occurs when an object is moved over a distance by an external force. Work is defined mathematically as the product of force and distance through the equation: \( Work = Force \times Distance \).The result of this calculation gives us work in Joules, with 1 Joule (J) being equivalent to a force of one Newton moving an object over a distance of one meter.
So, in our exercise:

• The weight lifter applies a force of 350 N over a distance of 2.00 m, resulting in work done of 700 J.
• The calculation looks like this: \( Work = 350 \text{ N} \times 2.00 \text{ m} = 700 \text{ J} \).
• Kinetic energy is transferred from the lifter to the weights, raising them to the new position, thus the work done is positive.

Simply put, Joules provide a measure for quantifying how much energy is transferred during the process, helping us understand how much effort is involved in tasks like lifting weights.