Work and More Work

With everything going on I forgot to give Honors Physics A their lab sheets for tomorrow. No matter, the experiment is pretty straightforward. The lab deals with energy and how it can be converted from one form to the next. You remember from other science courses that energy is a conserved value. It can neither increase nor decrease in a closed system, it can only be converted from one form to another. You will be looking at the conversion of energy from potential (energy available to do work) to kinetic (energy involved with active work) and back again in a mass-spring system. You will monitor changes in the amount of potential, kinetic energies and total mechanical energy in the system as the spring moves in the vertical plane. Reading over the section on conservation of energy in your chapter will help you prepare for the lab if you don’t remember this concept well from physical science or chemistry classes. Today, we took a stroll through work and its connection to kinetic energy. Keep in mind to read problems carefully to determine exactly what is being asked and the configuration of the forces acting on the object. We’ll go over the homework questions on Monday and relate them to the results you obtained in lab.

Physical Science B conducted a lab investigation about momentum. If you increase either mass or velocity, you expect an increase in an object’s momentum. The more acceleration time you gave your cart, the greater its velocity and momentum. When it collided with the box, the cart with the greater momentum had more to transfer to the box and the box was set in motion with a greater initial velocity. Since all the boxes experienced the same acceleration due to friction, a higher initial velocity meant the box traveled longer (and farter) than when it was hit by a lower-velocity cart. Physical Science E continued their exam review by practicing problems with universal gravitation. We really didn’t get any farther than that and it was agreed that a further day of preparation was required before assessment. So, for both B and E Blocks, the exam has been rescheduled to Monday.

Physics F and G discussed kinetic and potential energy and the ability of one to be converted into the other. Though both are reported in Joules, remember that objects have to be moving to have kinetic energy. At rest, they possess one or more forms of potential energy. We also connected work and energy changes. If an object experiences a change in either kinetic or potential energy, work had to be involved. If an object gains energy, work was done on the object; if the object loses energy, it did work on another object. The lab for this chapter deals with the energy types and the ability to be converted. Physics G will conduct the lab on Monday and Physics F follows on Tuesday.

Homework

Honors Physics A: 5.1 Section Review, Practice 5C
Physical Science B: Complete lab write up. Prepare and practice for Monday’s exam
Physical Science E: Prepare and practice for Monday’s exam
Physics F and G: Practice 5C #4, 5D #1, 5.2 SR #1,2,3,5