Phyics Tutor

decent · #1 Oct 30, 2009, 12:48 PM

Hello,

I'm not good in Physics, but I really want to learn. I'm just to slow to understand... So my question is, can anyone teach me for free about Physics?

Thank you,
decent

Unknown008 · Oct 31, 2009, 12:37 AM

Oh, please! Post your questions, post your work like I told you earlier!

Quote:

Originally Posted by decent

1. A 1600-kg car is moving at 20 m/s northward. A cement delivery truck with a mass of 2500 kg moving at 35 m/s southward collides head-on with the car. If they move together after collision, what is their common velocity?

2. A 25-g ball moving southward at 30 m/s collides with a 10-g ball moving along the same line with a velocity of 15 m/s southward. After collision, the 25-g ball attains a velocity of 22 m/s southward. What is the velocity of the 10-g ball?

Use the law of conservation of momentum; $m_1u_1 + m_2u_2 = m_1v_1+m_2u_2$

m_1 being the mass of the first body
m_2 the mass of the second body
u_1 the initial velocity of body 1
u_2 the initial velocity of body 2
v_1 the final velocity of body 1
v_2 the final velocity of body 2

m_1u_1 is the initial momentum of the first body
m_2U_2 is the initial momentum of the second body
m_1v_1 is the final momentum of the first body
m_2v_2 is the final momentum of the second body

m_1u_1 + m_2u_2 is the sum of initial momenta
m_1v_1 + m_2v_2 is the sum of final momenta

I cannot spoon-feed you all the time! It's time to work! Post your answers.



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