A rocket already in flight fires its second stage. This accelerates the rocket at a rate of 80 m/s/s to a velocity of 3600 m/s in 25 seconds. What was the rocket's velocity, v, just before the second stage was fired?

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is transformed ⇒ as it changes into other forms of energy.

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

If forces acting on an object are unbalanced. true or false