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Exploding whales Residents of Tainan learned a lesson in whale biology after the decomposing remains of a 60ton sperm whale exploded on a busy street, showering nearby cars and shops with blood and organs and stopping traffic for hours. The 56-foot-long whale had been on a truck headed for a necropsy by researchers, when gases from internal decay caused its entrails to explode in the southern city of Tainan. Residents and shop owners wore masks while trying to clean up the spilt blood and entrails. The whale had died on Jan. 17 after it beached itself on the southwestern coast of the island. As it was during the peak of summer with temperatures reaching over 100 degrees, the beached whale had been rotting in the heat for over 12 days until the explosion. The excessive heat had caused the gases within the whale’s digestive tract to expand to the point that the thick blubber couldn’t withstand the pressure and it exploded. The intestines, blood, excrement, and other fluids spread for a 2 block radius. Venders were selling drinks and treats to curious spectators are they watched the carnage. Newton’s Laws of Motion Forces, Inertia, & Friction Force: a push or a pull; any influence that tends to accelerate an object. Measured in Newtons (N) Inertia: the property of a body to resist change. Friction: the force that acts to resist the relative motion of objects or materials in contact. Newton’s First Law The law of Inertia Every object continues in a state of rest, or of motion in a straight line at a constant speed, unless it is compelled to change that state by forces exerted upon it. Things tend to keep doing what they’re already doing. Objects in a state of rest, stay at rest. Newton’s First Law Forces are needed to overcome any friction that may be present to get an object moving. Objects in motion, stay in motion. Mass and Inertia Mass: the amount of matter present in an object The amount of inertia depends on an object’s mass The more mass, the greater the inertia…and the greater the force it takes to change the state of motion. Mass and Volume Volume is a measure of space Mass is a measure of the amount of matter Measured in cubic centimeters (cm3) or liters (L) Measured in kilograms (kg) They are NOT EQUAL Which weighs more…a pound of feathers or a pound of lead? Which has more volume? Mass and Weight They are NOT the same thing! Mass depends on the # of and kind of atoms in an object. Weight varies with location, based on gravity. Mass is the same everywhere; weight is not. Weight Weight is a force It is measured in Newtons (N), just like forces are. A material that is 1 kg on Earth weighs 9.8 Newtons W = mg Weight is equal to mass times the acceleration due to gravity. Net Force Net force: the combination of all forces acting on an object. It is the net force that changes an object’s state of motion. Equilibrium: what the net force is equal to zero. If an object is resting on the table, the table is pushing on it with the same force that the book is pushing on the table. Lab Activity You and your lab partners will simulate a car crash for a passenger with AND without a seat belt. You will use only tape, string, a weight, your book, a small crate, and a graduated cylinder. Lab Questions What stopped the motion of the “doll” without a seat belt when the cart crashed to a stop? Why? Was there any difference for the “doll” with a seat belt? Why?