Calculate recoil velocity using conservation of momentum

[marcosdannyjp]

Homework Statement

A 70.0-kg man and a 55.0-kg woman holding a 2.50-kg purse on ice skates stand facing each other.

(a) If the woman pushes the man backwards so that his final speed is 1.50 m/s, with what average force did she push him,

assum ing they were in contact for 0.500 s? (b) What is the woman's recoil speed? (c) If she now throws her 2.50-kg purse

at him at a 20. 0° angle above the horizontal and at 4.20 m/s relative to the ground, what is her subsequent speed?

I know part a and b, but I need help with part c.

Homework Equations

kinematics equations
Newton's 2nd and 3rd law
conservation of momentum formula
impulse formula F*delta t= impulse = change in momentum

The Attempt at a Solution

the answer should be
2.09 m/s[/B]

 

[gneill]

Hi marcosdannyjp.

You need to show what you've tried so far, even if you didn't reach a satisfactory result. Helpers can't help you without first seeing your effort.

 

[amsabir094]

V(55)=2.5(2.45)cos20

 

[amsabir094]

V(55Kg)=2.50Kg(4.20m/s)cos20

 

[berkeman]

V(55)=2.5(2.45)cos20

V(55Kg)=2.50Kg(4.20m/s)cos20

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