Centre of Mass and System of Particles Important Questions for NEET Download PDF

Q1 A rigid body consists of a 3 kg mass located at
$r1=(2i^+5j^)m$ and a 2 kg mass located at
$r2=(4i^+2j^)m$. The position of centre of mass is

1. (145i^+195j^)m(514​i^+519​j^​)m
2. (145i^+195j^)m(514​i^+519​j^​)m
3. (176i^+146j^)m(617​i^+614​j^​)m
4. zero

 

Q2 A ping-pong ball strikes a wall normally with a velocity of 10 ms⁻¹. If the collision is perfectly elastic, find the velocity of the ball after impact

1. -20 ms⁻¹
2.  -5 ms⁻¹
3. 1.0 ms⁻¹
4. -10 ms⁻¹

 

Q3 A small uniform disc of radius 2 cm is cut from a disc of radius 6 cm. If the distance between their centers is 3.2 cm, what is the shift in the centre of mass of the disc?

1. 0.4 cm
2.  2.4 cm
3. 1.8 cm
4. 1.2 cm

 

Q4 Three particles of masses 1 kg, 3223​ kg, and 2 kg are located at the vertices of an equilateral triangle ABC of side a. The x, y coordinates of the centre of mass are (take A to be origin)

1. (5a9,2a33)(95a​,33​2a​)
2. (2a3,5a93)(32a​,93​5a​)
3. (5a9,5a93)(95a​,93​5a​)
4. (2a3,5a9)(32a​,95a​)

 

Q5 A 1 kg stationary bomb is exploded into three parts having mass ratio 1:1:3. Parts having same mass move in perpendicular directions with velocity 30 m/s, then the velocity of bigger part will be

1. 102102​ m/s
2. 1022​10​ m/s
3. 152152​ m/s
4. 1522​15​ m/s

 

Q6 A body falling from a height of 10 m rebounds from hard floor. If it loses 20% energy in the impact, then coefficient of restitution is

1. 0.89
2. 0.56
3. 0.23
4. 0.18

 

Q7 A uniform metal disc of radius R is taken and out of it, a disc of diameter R22R​ is cut off from the end. The centre of mass of the remaining part will be situated at ------------

1. R/10 from the centre
2. R/15Rfrom the centre
3. R/5 from the centre
4. R/20​ from the centre

Centre of Mass and System of Particles Important Questions for NEET PDF