Center of Mass — Practice Quiz

Question 1

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

Accepted Answer

(3,0)

Answer

(2,0)

Answer

(2.5,0)

Answer

(5,0)

Question 2

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

Accepted Answer

Continues on the original projectile path

Answer

Falls straight down

Answer

Stops instantly

Answer

Moves randomly

Question 3

COM of a uniform circular ring lies:

Accepted Answer

At the center (in the hole)

Answer

On the ring itself

Answer

Outside the ring

Answer

At one edge

Question 4

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

Accepted Answer

F_ext = M·a_COM

Answer

F_ext = Σ m_i a_i

Answer

F_ext = 0 always

Answer

F_ext depends on internal forces

Question 5

If no external force acts, the COM:

Accepted Answer

Moves with constant velocity

Answer

Stops

Answer

Accelerates

Answer

Oscillates