1) What is centre of mass? a) It is the mass of a body located at its centre. b) It is the point on an object where its mass appears to be concentrated. c) It is the amount of matter contained in a body. d) It is the mass of a body at a particular point on an object  2) Where on the insert image 2.1 of the plumbline does its centre of mass occur? a) The centre of mass occurs at a point along the plumbline  b) The centre of mass occurs at the centre of the lamina. c) The centre of mass occurs between A and B. d) The centre of mass occurs between A and C. 3) On the insert figure 3.1 what does the point of intersection of the first two lines signify? a) Correctly located center of mass b) Center of body c) Amount of matter d) Center of mass  4) What does the third line (Line 3) in figure 3.1 of question 3 indicate about the position of your located centre of mass? a) Center of mass was not there. b) Center of mass was wrongly located  c) Centre of mass was correctly located  d) Center of mass was changing in amount 5) Why is the idea of centre of mass of an object important? a) Because it helps to ascertain the stability of an object. b) Because it helps to maintain an object. c) Because it helps to find unstable equilibrium. d) Because center of gravity will help to calculate weight.. 6) What precaution would you take when locating the centre of mass of plane lamina? a) Making sure that the swings when drawing its position on lamina. b) Making sure that the pin on which the lamina hangs is made of steel. c) Making sure that the lamina is fixed. d) Making sure that the holes made in plane lamina nearer to the edge of lamina are spread as far apart as possible. 7) Four objects are situated along the y-axis as follows: a 2 kg object is at +3 m, a 3 kg object is at +2.5 m, a 2.5 kg object is at the origin, and a 4 kg object is at -0.5 m. Where is the center of mass of these objects?   a) 0.5m b) 1.0m c) 3.0m d) 4.0m 8) A baseball bat with uniform density is cut at the location of its center of mass as shown in the figure. After the cut, which piece has the smaller mass? a) The longer part of the cut baseball bat. b) Both cuts have equal masses  c) The shorter part of the cut baseball but d) The uncut baseball bat. 9) The broom was balanced on the tip of the finger as shown in the insert figure. Why is the centre of mass located at the point of balance and not at the centre of its length?  a) Because at centre of length less mass than average mass of the broom appears to be concentrated there. b) Because the stick is too long for centre of mass to be located along it. c) Because the head of the broom has more brushes.  d) Because the broom is not uniformly shaped 10) Why is the concept of center of mass useful? a) Because center of mass makes an object accelerate faster. b) Because it helps to solve problems of mechanics that are based on rotation of a rigid body. c) Because center of mass may lie within or outside an object. d) Because it helps us understand forces