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mmoadi
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Homework Statement
A cart is driving on straight tracks with a velocity of 2 m/s. In the opposite direction, with an angle of 60º according to the tracks, a child with a mass of 2 kg is running with a velocity of 2m/s, he jumps on the cart and stays there.
- Find the mass of the cart, if its velocity is reduced to 1 m/s when the child jumps onto it.
- What is the thrust force (impulse) perpendicular to the tracks?
Picture:
http://www.slide.com/s/JuaPVKdK7j_16GybLEom3mA1r3ATs8QQ?referrer=hlnk
Homework Equations
p= mv
F= ma
The Attempt at a Solution
First part: Find the mass of the cart, if its velocity is reduced to 1 m/s when the child jumps onto it.
Conservation of the moment:
m(2)= 20 kg, v(1-initial)= v(2-initial)= 2 m/s, v(1-final)= 1 m/s, v(2-final)= 0 m/s
m(1)v(1-initial) + m(2)v(2-initial)= m(1)v(1-final) + m(2)v(2-fianl)
m(2)v(2-initial)= m(1)v(1-final) - m(1)v(1-initial)
m(2)v(2-initial)= m(1)*(v(1-final) - v(1-initial))
m(1)= m(2)v(2-initial) / (v(1-final) - v(1-initial))
m(1)= 40 kg
Are these calculations correct?
For the second part, I'm kind of confused to find the direction of the thrust force. Can someone give me a hint?
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