A wooden block of mass M resting on a frictionless, horizontal surface is attach

Question

A wooden block of mass M resting on a frictionless, horizontal surface is attached to a rigid red of length ( and of negligible mass. The rod is pivoted at the other end. A bullet of mass m traveling parallel to the horizontal surface and perpendicular to the rod with speed v hits the block and becomes embedded in it. What is the angular momentum of the bullet-block system about a vertical axis through the pivot? (Use any variable or symbol stated above as necessary. )What fraction of the original kinetic energy of the bullet is converted into internal energy in the system during the collision? (Use any variable or symbol stated above as necessary. )A wad of sticky clay of mass m and velocity v is fired at a solid cylinder of mass M and radius R (see figure). The cylinder is initially at rest and is mounted on a fixed horizontal axle that runs through its center of mass. The line of motion of the projectile is perpendicular to the axle and at a distance d

Explanation / Answer

a) L = Li = m v l

b) KE initial = 1/2 mv^2

Li = Lfinal

m v L = (m + M) L^2 w

m v =(m + M) v final

vfinal = m v/(m + M)

KEfinal = 1/2 (m + M) vfinal^2 = 1/2 m^2 v^2/(m + M)

dKE = KEfinal - KE intitial = 1/2 m^2 v^2/(m + M) - 1/2 mv^2

= ( 1/2 m^2 v^2 - 1/2 m^2 v^2 - 1/2 m M v^2)/(m + M) = - 1/2 m M v^2/(m + M)

dKE/Ki = 1/2 m M v^2/(m + M)/( 1/2 m v^2) = M/(m + M)

2) Li = L final

m v d = ( 1/2 M R^2 + m R^2) w

w = m v d/( 1/2 M R^2 + m R^2)

b) no it is not, since its inelastic

c) linear momentum is not since axle gives force in x direction (but not torque)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.