Hannah Spalding's Science Blog

 Textbook notes:  Force: a push or pull  Newton's First Law Objects at rest remain at rest, while objects in motion stay in motion unless acted on by an unbalanced external force or every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.  Every object and every motion are all acted on by forces at all times A force is a push or a pull on an object resulting from the object's interaction with another object There needs to be another object acting on it in some way  Why do things move?  Need to apply another force to it that is strong enough to make it move In order to move, one side must have a bigger pull or force  The forces must be unbalanced to make something move  Objects remain at rest while objects in motion stay in motion unless acted on by an unbalanced external force  Why do things stop moving?  Friction  A force that holds back t...

 My main takeaways from this week's focus topic/unit:  Book Notes What are wind turbines?  Wind energy = important & growing source of renewable energy  Wind turbines convert kinetic energy from wind --> mechanical energy through rotational movement of blades. Electric generator converts mechanical energy from spinning blades to electric energy that can be used to power many sources Wind energy is a form of kinetic energy Rotation of blades (turbine) & gear box is a form of mechanical energy  Generator has a spinning rotor causing a rotating magnetic flux inside stator of coils to create current as a form of electrical energy (induction)  How do wind turbines create electricity?  Blades capture air & spin  Bernoulli's principle: molecules have farther to go over the top of a wing * therefore travel faster. Greater speed provides less pressure than forces on the bottom of the wing, and plane is pushed off the ground.  Wind comes...

  This week, we talked about electricity. Here are some of my main takeaways:  Electricity : the movement of electrons from one atom to another  Electrons are negatively charged particles Current:  flow of electrical charge  Circuit:  a path through which electricity can flow Closed circuit: circle is closed, so energy is flowing  Open circuit: circle is opened, so energy cannot flow  Making a circuit, you need:  Battery (source of potential energy in the form of electricity)  Copper wire (path for electricity to flow through)  Light bulb (uses electricity from the circuit to light up)  Anode:  negative side of a battery  Cathode: positive side of a battery  Series circuit: electricity flows through one continuous loop (holiday lights: if 1 light burns out, the entire string will not work because the energy flow was interrupted) Parallel circuit: electricity flows through multiple loops in the same circuit (holid...

Pendulums: Week 2 Major Concepts/Big Ideas In a simple pendulum (with no friction), mechanical energy is conserved Total mechanical energy = kinetic energy & gravitational potential energy As the pendulum swings, there is a constant exchange between kinetic energy & gravitational potential energy Independent variable: angle  Dependent variable: weight, length, drop technique, pendulum design, time The ONLY variable that really matters = length  Shorter pendulum, more swings Longer pendulum, less swings Lab Results: