7/17/2019 Forces and Motion

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Forces and Motion

7/17/2019 Forces and Motion

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Force

•  A push or pull upon an object resulting from theobject's interaction with another object.

• measured in Newton[N]

Newton’s econd law of motion !

• "hen two or more forces act upon a bod# then

there e$ists a resultant force on that bod#. % &alanced ! N(at rest )constant speed along astraight line

 % *nbalanced

F+ma

7/17/2019 Forces and Motion

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• "eight(",! Force of gra-it# that acts upon

a bod#.

 % measured in Newtons[N]

• acceleration due to gra-it# (g,! Acceleration

caused b# pull of arth's gra-it#[m)s/]

• mass remains same but 'g' differs on moon

and other planets and hence weight changes

W =mg

7/17/2019 Forces and Motion

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• 0erminal -elocit#!

• Momentum ! m $ -[1gm)s]

• 2rinciple of con-ersation of momentum!0he total momentum of two objects before

collision is e3ual to the total momentum after

collision

• 4mpulse ! F $ t [Ns]4mpulse is the change in momentum

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5uestions

6. A wooden bar is pi-oted at its center so

that it can rotate freel#. 0wo e3ual forces

are applied to the bar. 4ndicate the

position of the two forces[/67!Ma#8

9une]