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## Main Question or Discussion Point

hi guys many thanks in advance for any help, im revising for an exam and got stuck on this question:

"A supernova of energy 10^44 J explodes in interstellar matter of density n0 = 10^6

m^−3 and pressure Pi = 3*10^−14 N m^−2. Estimate how much gas (mass) can

be disturbed by this supernova. The expansion happens at a velocity Vs = 4 km s^−1."

The answer sheet says the following:

"This is in the snowplough phase. Using the snowplough equations with V0 = 250 km s−1 and R0 = 7*10^17 m gives a time t = 1.7*10^14 s, radius R = 2.8*10^18 m and a mass affected M = 10^5 M⊙."

So basically i have no idea what equation/equations have been used or where the values for the variables. thanks again

"A supernova of energy 10^44 J explodes in interstellar matter of density n0 = 10^6

m^−3 and pressure Pi = 3*10^−14 N m^−2. Estimate how much gas (mass) can

be disturbed by this supernova. The expansion happens at a velocity Vs = 4 km s^−1."

The answer sheet says the following:

"This is in the snowplough phase. Using the snowplough equations with V0 = 250 km s−1 and R0 = 7*10^17 m gives a time t = 1.7*10^14 s, radius R = 2.8*10^18 m and a mass affected M = 10^5 M⊙."

So basically i have no idea what equation/equations have been used or where the values for the variables. thanks again