Alice each push a puck to have them collide on an air table. In a particular sys

Question

Alice each push a puck to have them collide on an air table. In a particular system of axis, Alice's puck (mass 450 g) moves with a velocity of (30 i + 40j) cm/s. In the same system of axis, Bob's puck (mass 600 g) moves with a velocity of (-25 i - 75 j) cm/s. After the collision, Alice's puck is moving with a velocity of (25 i - 15 j) cm/s and Bob's puck is moving with a velocity of (20 i- 35 j) cm/s. What is the total momentum of the system before the collision What is the total kinetic energy of the system before the collision What is the total momentum of the system after the collision What is the total kinetic energy of the system after the collision Was momentum conversed in the collision Was kinetic energy conserved What type of collision would this be

Explanation / Answer

Ma=0.45kg, Va1=30i^+40j^

Mb=0.6kg, Vb1=-25i^-75j^

Va2=25i^-15j^ , Vb2=20i^-35j^

a)Before collision

Total Momnetum (P1)= Ma*Va1+Mb*Vb1 =0.45*(30i^+40j^)+0.6*(-25i^-75j^) =-1.5i^-27j^ kg.m/s

Magnitude of P=sqrt(1.5^2+27^2)=27.04

K.E1=1/2*Ma*Va1^2+1/2*Mb*Vb1^2 where Va=sqrt(30^2+40^2),Vb=sqrt(25^2+75^2)

K.E1 =1/2*0.45*(sqrt(30^2+40^2))^2+1/2*0.6*(sqrt(25^2+75^2))^2=2437.5J

b)After collision

Total Momnetum (P2)= Ma*Va2+Mb*Vb2 =0.45*(25i^-15j^)+0.6*(20i^-35j^) =23.25i^-27.75j^ kg.m/s

Magnitude of P=sqrt(23.25^2+27.75^2)=36.20kg.m/s

K.E2=1/2*Ma*Va2^2+1/2*Mb*Vb2^2 where Va2=sqrt(25^2+15^2),Vb=sqrt(20^2+35^2)

K.E2 =1/2*0.45*(sqrt(25^2+15^2))^2+1/2*0.6*(sqrt(20^2+35^2))^2=678.75J

c)Neither total momentum nor total kinetic energy is conserved in this collision.

Inelastic because KE is not conserved

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