Question

The four particles shown in Fig. connected by rigid rods. The or igin is at the center of the rectangle. If the system rotate in the xy plane about the z axis with an angular speed of 8.00 rad/s, calculate yim) 9.00 kg 2.00kg 04: The moment of inertia of the system about the z axis (A) 143Kg. m2 (B) 65Kg.m2 (C) 78Kg. m2 (D) 52Kg m2 (E) 91Kg.m2 6.00 m x(m) 0 CS: The rotational kinetic energy of the system. ( A) 3.50 × 1oY (B) 4.58 × 103, (C) 1.14 × 10ッ (D) 1.78 x 10J (E)2.57 x 10 200 kg 4.00 kg Q6 A '0.500-kg ball is thrown straight up into the air with an initiai spe ed of 15.0 m/s. Find the momen tuin of The ball at halfway up to its maximum height (A) 5.:30Kg.ms (B)1.06Kg.ms 212Kg.s (D)3.18g.ms-1 (E) 4.24Kg.ms-

Answer 1

Q4)

Iz = Ix + Iy = My^2 + Mx^2

= 2(3^2+2^2) + 3(3^2+2^2) + 2(3^2+2^2) + 4(3^2+2^2)

= 11 x 13 = 143 kgm^2

Q5)

K = 1/2 I w^2

- 143/2 x 8^2 = 4576 J = 4.58 kJ

Q6

h = v^2/2g = 15^2 / 20 = 11.25 m

v = (2gh)^0.5 = (2x10x5.625)^0.5

= 10.61 m/s halfway

p = mv = 0.5x10.61 = 5.3 kgm/s