Conservation momentum questions help

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SUMMARY

This discussion focuses on momentum conservation principles applied to two scenarios: a collision between two masses and the momentum change of a space probe. In the first scenario, a 1.0 kg mass collides with a stationary mass, leading to the conclusion that both masses can move together at the same speed if the stationary mass equals 1.0 kg. In the second scenario, a 100 kg space probe traveling at 5000 m/s fires a thruster producing 500 Newtons of force for 7 minutes, requiring calculations for impulse, new momentum vector, new speed, and propellant mass used.

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  • Understanding of conservation of momentum
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  • Basic knowledge of vector components in physics
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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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