Jowin
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A festival rocket is ejecting 0.05 kg of gases per second at a velocity 400m/s The accelerating force on the is? The formula given in the book is F=dp/dt What does the formula mean
Accelerating force due to ejection
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The formula is known as Newton's second law and states that the net force acting on a body is equal to the rate of change of the [linear] momentum of the body.Jowin said:A festival rocket is ejecting 0.05 kg of gases per second at a velocity 400m/s The accelerating force on the is? The formula given in the book is F=dp/dt What does the formula mean
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Welcome to PF!
Hi Jowin! Welcome to PF!
I'll just add:
p is momentum, which is mass times velocity: p = mv.
F = dp/dt is the official version of good ol' Newton's second law …
so it's F = d(mv)/dt = m dv/dt + v dm/dt, which for fixed m is F = m dv/dt, which is probably what you recognise.
But for space rockets and festival rockets, m changes, so the official version has to be used!
Hi Jowin! Welcome to PF!
Jowin said:A festival rocket is ejecting 0.05 kg of gases per second at a velocity 400m/s The accelerating force on the is? The formula given in the book is F=dp/dt What does the formula mean
Hootenanny said:
I'll just add:
p is momentum, which is mass times velocity: p = mv.
F = dp/dt is the official version of good ol' Newton's second law …
so it's F = d(mv)/dt = m dv/dt + v dm/dt, which for fixed m is F = m dv/dt, which is probably what you recognise.
But for space rockets and festival rockets, m changes, so the official version has to be used!