System of Particles & COM — Previous-Year Questions

Q1. Two particles of mass 2 kg and 3 kg are at positions (0,0) and (5,0). COM:

Q2. An explosion in mid-air: the COM of the fragments:

Q3. COM of a uniform circular ring lies:

Q4. Newton's 2nd law applied to a system of particles is:

Q5. If no external force acts, the COM:

Q1. A bomb of mass 5 kg moving at 4 m/s explodes into 3 fragments. COM velocity afterward:

Q2. Two particles of mass 1 kg and 3 kg are at rest. A force of 4 N is applied to the 1-kg particle for 2 s. COM velocity:

Q3. Earth-Moon system's COM lies:

Q4. A projectile of mass 4 kg breaks into two pieces of 1 kg and 3 kg at the highest point. The 3-kg piece falls vertically down. COM of fragments still:

Q5. Internal forces in a system:

Q1. Momentum of a 0.5 kg ball moving at 10 m/s:

Q2. Newton's 2nd law in its most general form is:

Q3. Total momentum of an isolated system:

Q4. A 2 kg ball at 6 m/s has momentum and KE equal to:

Q5. Two bodies of mass 2 kg and 8 kg have equal momenta. Their KE ratio is:

Q1. A 0.2 kg ball moving at 10 m/s is struck back at 15 m/s. Impulse:

Q2. Impulse has SI units:

Q3. Airbags reduce the force on a passenger during a crash by:

Q4. Force of 500 N acts for 0.02 s. Impulse:

Q5. On an F-t graph, the area equals:

Q1. A 10 kg shell at rest explodes into a 4 kg piece moving at 30 m/s and another piece. Velocity of the other piece:

Q2. A 5 g bullet fired at 600 m/s from a 2 kg gun. Recoil speed of gun:

Q3. Momentum is conserved in:

Q4. Two equal masses moving with equal but opposite velocities undergo perfectly inelastic collision. Their COM:

Q5. Why does an astronaut floating in space throw a tool in one direction to move in the opposite?

Q1. A particle of mass 2 kg moves at 3 m/s along a straight line at perpendicular distance 4 m from origin. L:

Q2. If a particle's velocity passes through the origin, its L about origin is:

Q3. An astronaut pulls in their arms while floating. Their:

Q4. Kepler's 2nd law (equal areas in equal times) is equivalent to:

Q5. Units of angular momentum are:

Q1. A rocket ejects mass at rate 10 kg/s with exhaust velocity 2000 m/s. Thrust:

Q2. Tsiolkovsky equation gives Δv proportional to:

Q3. Why are rockets multistage?

Q4. If u_e doubles and m_0/m_f stays the same, final velocity Δv:

Q5. Ion thrusters have higher Isp than chemical rockets because: