11. [-/0.5 Points] DETAILS KATZPSEF1 10.P.066. MY NOTES PRACTICE ANOTHER A parcel moving in a horizontal direction with speed vo = 13 m/s breaks into two fragments of weights 1.1 N and 1.8 N, respectively. The speed of the larger piece remains horizontal immediately after the separation and increases to V1 8 = 27 m/s. Find the necessary speed and direction of the smaller piece immediately after the separation. (Assume the initial direction of the parcel is positive. Indicate the direction with the sign of your answer.) m/s 12. [-/0.5 Points] DETAILS KATZPSEF1 10.P.070. MY NOTES PRACTICE ANOTHER A ballistic pendulum is used to measure the speed of bullets. It comprises a heavy block of wood of mass M suspended by two long cords. A bullet of mass m is fired into the block horizontally. The block, with the bullet embedded in it, swings upward (see figure below). The center of mass of the combination rises through a vertical distance h before coming to rest momentarily. In a particular experiment, a bullet of mass 34.0 g is fired into a wooden block of mass 11.6 kg. The block-bullet combination is observed to rise to a maximum height of 19.2 cm above the block's initial height. m M (a) What is the initial speed of the bullet? m/s (b) What is the fraction of initial kinetic energy lost after the bullet is embedded in the block? (Enter your answer to at least three significant figures.) KE - KEM+m = KE m13. [-/1 Points] DETAILS SERPSE10 9.2.P.005. MY NOTES PRACTICE ANOTHER Two blocks of masses m and 3m are placed on a frictionless, horizontal surface. A light spring is attached to the more massive block, and the blocks are pushed together with the spring between them as shown in the figure below. A cord initially holding the blocks together is burned; after that happens, the block of mass 3m moves to the right with a speed of V 3m = 2.55 m/s. m MM 3m Before a V3m 3m After b (a) What is the velocity of the block of mass m? (Assume right is positive and left is negative.) m/s (b) Find the system's original elastic potential energy, taking m = 0.470 kg. J (c) Is the original energy in the spring or in the cord? O in the spring O in the cord (d) Explain your answer to part (c). This answer has not been graded yet. (e) Is the momentum of the system conserved in the bursting-apart process? Yes O No (f) Explain how that is possible considering there are large forces acting. his answer has not been graded yet. (9) Explain how that is possible considering there is no motion beforehand and plenty of motion afterward?14. [-/0.5 Points] DETAILS SERPSE10 9.5.OP.018. MY NOTES PRACTICE ANOTHER As shown in the figure, a billiard ball with mass my is initially at rest on a horizontal, frictionless table. A second billiard ball with mass m, moving with a speed 2.00 m/s, collides with m2. Assume m, moves initially along the +x-axis. After the collision, m, moves with speed 1.00 m/s at an angle of 0 = 51.0 to the positive x-axis. (Assume m, = 0.200 kg and m2 = 0.300 kg.) After the collision Uf sin e Before the collision if cos e e Vli Jo Ugf COS Q Way sino - mg Nof a b (a) Determine the speed (in m/s) of the 0.300 kg ball after the collision. m/s (b) Find the fraction of kinetic energy transferred away or transformed to other forms of energy in the collision. IAKI K ; 15. [-/0.5 Points] DETAILS SERCP11 6.2.P.030. MY NOTES PRACTICE ANOTHER Three ice skaters meet at the center of a rink and each stands at rest facing the center, within arm's reach of the other two. On a signal, each skater pushes himself away from the other two across the frictionless ice. After the push, skater A with mass my = 90.0 kg moves in the negative y-direction at 4.00 m/s and skater B with mass my = 70.0 kg moves in the negative x-direction at 2.00 m/s. Find the x- and y-components of the 95.0 kg skater C's velocity (in m/s) after the push. HINT VO = m/s V CV m/s Need Help? Read It Watch It 16. [-/0.5 Points] DETAILS SERCP11 6.4.P.032. MY NOTES PRACTICE ANOTHER An archer shoots an arrow toward a 300-g target that is sliding in her direction at a speed of 2.45 m/s on a smooth, slippery surface. The 22.5-g arrow is shot with a speed of 37.0 m/s and passes through the target, which is stopped by the impact. What is the speed of the arrow after passing through the target? m/s Need Help? Read It17. [-/1 Points] DETAILS SERPSE10 9.5.P.022.MI. MY NOTES PRACTICE ANOTHER A 93.0-kg fullback running east with a speed of 4.20 m/s is tackled by a 97.0-kg opponent running north with a speed of 3.00 m/s. (a) Explain why the successful tackle constitutes a perfectly inelastic collision. This answer has not been graded yet. (b) Calculate the velocity of the players immediately after the tackle. magnitude m/s direction . north of east c) Determine the mechanical energy that disappears as a result of the collision. Account for the missing energy. This answer has not been graded yet. Need Help? Master It 18. [-/1 Points] DETAILS KATZPSEF1 12.P.005.MI. MY NOTES PRACTICE ANOTHER A ceiling fan is rotating counterclockwise with a constant angular acceleration of 0.65x rad/s about a fixed axis perpendicular to its plane and through its center. Assume the fan starts from rest. (a) What is the angular velocity of the fan after 2.6 s? (Enter the magnitude.) rad/s (b) What is the angular displacement of the fan after 2.6 s? (Enter the magnitude.) rad (c) How many revolutions has the fan gone through in 2.6 s? rev Need Help? Master It