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NIS – PHYSICAL SCIENCE. Lecture 10 Laws of Motion Ozgur Unal. First Law of Motion. First law of Newton describes how an object moves when the net force on the object is zero .
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NIS – PHYSICAL SCIENCE Lecture 10 Laws of Motion OzgurUnal
FirstLaw of Motion Firstlaw of Newton describeshow an objectmoveswhenthe net force on theobject is zero. Accordingtothefirstlaw of motion, ifthe net forceacting on an object is zero, theobjectremains at rest, oriftheobject is moving, it continuesmoving in a straightlinewithconstantspeed. • Examples: • Book on a table • A car moving at constant • velocity
InertiaandMass • Inertia is thetendency of an objecttoresist a change in itsmotion. • Anythingthat has mass has also an inertia. Massincreasesinertia. Checkthisout! Whydoestheobject on the cart keepmoving? • Whathappenswhen I securetheobject on the car by a tape? • Whathappens in a car crash? • Why is it importanttousesafetybelts? • www.youtube.com/watch?v=rsqE-uOtMM4
SecondLaw of Motion • Iftheball is heavy (moremass), is it easierorhardertothrow it withgreateracceleration? Imagineyourselfthrowing a ball. Ifyouthrowtheballwith a greaterforce, will it acceleratemoreorless? • Newton’ssecondlaw of motionrelatestheforce on an objecttoitsaccelerationandmass.
NIS – PHYSICAL SCIENCE Lecture 11 SecondLaw of Motion OzgurUnal
SecondLaw of Motion Newton’ssecondlaw of motionstatesthattheacceleration of an object is in thesamedirection as the net force on theobjectandthattheacceleration can be calculatedfromthefollowingequation: a = Fnet / m • Fnet = m * a • What is theunit of force?
SecondLaw of Motion • Knownvalues: • Mass of thehelicopter: m = 4,500 kg • Netforce on thehelicopter: Fnet = 18,000 N • Unknownvalue: • Acceleration: a = ? • a = Fnet / m = 18,000 N / 4,500 kg = 4 m/s2 Ifthemass of a helicopter is 4,500 kg, andthe net force on it is 18,000 N, what is thehelicopter’sacceleration?