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Malina Gonzalez October 4th, 2020 Dr Hoxha Phys 111-01 Lab 5 “ Work & Energy” Background: Mechanical energy is the energy of an object based on its motion or position. It is the sum of potential and kinetic energy. According to the principle of the conservation of mechanical energy the total energy in a system will stay constant if the forces acting are conservative forces. If a system has no friction, all forces should be conservative. There are two types of mechanical energy: kinetic and potential. Kinetic energy is the energy of mass in motion and it disappears as the speed of object is zero. The formula for kinetic energy follows by: ࠵?࠵?=½࠵?࠵?2 where m = mass and v = speed. Potential energy is energy that is stored in an object because of its position in relation to another position of zero. There are a few types of potential energy such as: gravitational potential energy, electrostatic potential energy, and nuclear potential energy. The formula for gravitational potential energy follows by: PEgrav= m *• g • h where m = mass, h = height of object, and g = gravity (9.8N/kg). The formula for elastic spring potential energy follows by: PE = ½kx^2 where x = the displacement of the spring from its equilibrium position. Pre Lab Questions: 1. In a tug of war, one team is slowly giving way to the other. Describe the work done by the winning team and the work done by the losing team. 2. A projectile of mass m=2kg is fired with an initial velocity Vs= 40 m/s at an angle 30 degrees to the horizontal. What is its potential and kinetic energy after t = 1.8 seconds? Assume no friction.