Conservation momentum questions help

AI Thread Summary
In the discussion, participants explore two problems related to conservation of momentum. For the first problem, they analyze whether two masses can move together post-collision and determine the conditions for this scenario, as well as the possibility of them moving in opposite directions. The second problem involves a space probe changing direction after firing a thruster, with participants calculating impulse, new momentum, speed, and the mass of propellant used. The conversation highlights the application of momentum equations and the challenges faced in solving these physics problems. Overall, the thread emphasizes the importance of understanding conservation principles in collision and propulsion scenarios.
philadelphia
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1. A 1.0 kg mass moving with a velocity v m/s strikes a stationary mass (assume no frictional losses).
a. Is it possible for both masses to move in the same direction and at the same speed after the collision? If so, find the value of the stationary mass.
b. Is it possible for both masses to move in OPPOSITE directions but with the same speed after the collision? If so, find the value of the stationary msss.


Homework Equations


m1v1=m2v2

The Attempt at a Solution


Not sure if this is the right path for (a)
m1 = 1kg
v2 = 0 m/s

a. after collision
v1 = v2 = v = 5(random variable to plug)
(1kg)(5m/s) = m2(5m/s)

b. i don't get help help me with a step

2. A space probe of mass 100kg is traveling due East at 5000m/s. It fires a thruster for 7 minutes to change direction. If the engine produces 500 Newtons of force in a direction 45 degrees North of West.
a)Find the impulse
b)FinD the new momentum vector of the spacecraft
c)Find the new speed of the spacecraft and its direction
d) If the fuel is ejected at 3000m/s find the mass of the propellant used in the burn



Homework Equations


F\Deltat = m\DeltaV
m= 100 kg
v=5000 m/s
t= 7min = 420 secs

500N 45 degrees NoW

The Attempt at a Solution


a) m\DeltaV = 100kg(5000m/s) = 500000 kg m/s
b) I am stuck afterwards I am guessing its cos(45)500N * 420 seconds
c) answer from b divide by 100kg (F\Deltat / m = V)
d) I don't know
 
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1b) is simply if it is an elastic collision, meaning Vf1=-Vf2. Entirely possible,

2 is just a stupid question. There is no east in space...
a) your answer looks correct...
b) P=mv use conservation of momentum and the impulse you found to find its new momentum. I=Pfinal - Pinitial
c) you seem to have a handle on.
d) I am assuming this is more simple than I am thinking. However the simplest I can think of is that impulse is the integral of force, Impulse is also change in momentum, which gives you that by Newtons 2nd and 3rd laws the force exerted by the fuel acts equally on the rocket. The force of thrust is Dm/dt times V so that may help you. If none of that rant helps say so I am going to go solve this as an exercise of my own so I will have it shortly.
 
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