What are the potential and kinetic energies when an individual lifts an 882.9N barbell overhead to a height of 2m?
The potential energy of the barbell lifted overhead is 1765.8 J, and the kinetic energy is 0 J. Potential energy is calculated using the formula P.E = mgh, where m is the mass of the object, g is the gravitational acceleration, and h is the height the object is raised to. In this scenario, with a barbell mass of 90 kg, gravitational acceleration of 9.8 m/s^2, and raising the barbell to a height of 2m, the potential energy is 1765.8 J. As for the kinetic energy, it is 0 J because the barbell is stationary at the height of 2m.
Understanding Potential and Kinetic Energies
Potential Energy:
Potential energy is the energy stored in an object due to its position or state. In this case, when the barbell is lifted to a height of 2m, it gains potential energy because of its elevated position. The gravitational potential energy is calculated as:
P.E = mgh
Where:
m = mass of the object (90 kg)
g = gravitational acceleration (9.8 m/s^2)
h = height from which the object was raised (2m)
Substitute the values into the formula:
P.E = 90 kg * 9.8 m/s^2 * 2m
P.E = 1765.8 J
Therefore, the potential energy of the barbell lifted overhead is 1765.8 Joules.
Kinetic Energy:
Kinetic energy is the energy an object possesses due to its motion. When an object is in motion, it has kinetic energy. However, in this scenario, the barbell is held overhead and stationary at a height of 2m. Since it is not in motion, the kinetic energy is 0 J.
In summary, when an individual lifts an 882.9N barbell overhead to a height of 2m, the potential energy is 1765.8 J, and the kinetic energy is 0 J.
Understanding the concept of potential and kinetic energies is essential in physics to comprehend the behavior and interactions of objects in various situations.