System of Particles

Question 1

Xcom for the discrete particle system

Answer 1

m1x1+m2x2/m1+m2

Question 2

What is the r vector of a continuous body?

Answer 2

∫r.dm/∫dm

Question 3

Ycom of semi circular ring of mass m and radius R

Answer 3

2R/π

Question 4

Ycom of semi circular disc of mass m and radius R

Answer 4

4R/3π

Question 5

Conservation of Linear Momentum

Answer 5

Fext = 0, Acom= 0
Intial Momentum = FInal Momentum

Question 6

Impulse of a force

Answer 6

Change in momentum
Unit: Newton Second

Question 7

Perfectly Elastic Collision

Answer 7

Energy lost during deformation has been regained during reformation.
No loss of energy and no external force, hence the coefficient of restitution and conservation of linear momentum can be applied.

Question 8

Perfectly Inelastic Collision

Answer 8

No reformation happens and as energy lost during deformation is not gained back during reformation, hence some energy is lost.
Coefficient of restitution cannot be applied and conservation of linear momentum can be applied.

Question 9

Inelastic collision

Answer 9

Energy regained during reformation is less than the energy lost during deformation, hence some energy is lost.

Question 10

Head-on collision

Answer 10

Velocities of both bodies are along the line of impact

Question 11

Oblique Collision

Answer 11

Velocities not along the line of impact

Question 12

Coefficient of restitution

Answer 12

Velocity of separation along line of impact/ Velocity of approach along line of impact