Object1 of mass 6 kg moving down at -35° and 20 m/s collides and sticks to object2 of mass 8 kg which was initially moving up at 50° and 25 m/s. What is the final velocity of the combined objects? O 21.81 m/s

A 44.0-kg child finds himself trapped on the surface of a frozen lake, 10.0 m from the shore. The child slips with each step on the frictionless ice and remains the same distance from the shoreline. Egged on by his parents, he throws a 0.750-kg ball he is carrying toward the center of the lake with a horizontal speed of 1.50 m/s, in the direction opposite that of the shoreline. a. Does the act of throwing the ball cause the child to move? If so, what are the speed and the direction of his motion with respect to the Earth? b. What are the forces acting on the child when he throws the ball?

An elephant and a hunter are having a confrontation. a. Calculate the momentum of the 2000.0-kg elephant charging the hunter at a speed of 7.50 m/s. b. Calculate the ratio of the elephant’s momentum to the momentum of a 0.0400-kg tranquilizer dart fired at a speed of 600 m/s. c. What is the momentum of the 90.0-kg hunter running at 7.40 m/s after missing the elephant?

Your physical education teacher throws a baseball to you at a certain speed and you catch it. The teacher is next going to throw you a medicine ball whose mass is ten times the mass of the baseball. You are given the following choices: You can have the medicine ball thrown with (a) the same speed as the baseball, (b) the same momentum, or (c) the same kinetic energy. Rank these choices from easiest to hardest to catch.

This is a symbolic version of Problem 35. A railroad car of mass M moving at a speed v1 collides and couples with two coupled railroad cars, each of the same mass M and moving in the same direction at a speed v2. (a) What is the speed vf of the three coupled cars after the collision in terms of v1 and v2? (b) How much kinetic energy is lost in the collision? Answer in terms of M, v1, and v2.

Problems 44 and 45 are paired. C A model rocket is shot straight up. As it reaches the highest point in its trajectory, it explodes in midair into three pieces with velocities indicated by the arrows in Figure P10.44, as viewed from directly above the explosion. Rank the mass of each piece in order from smallest to largest and justify your answer. FIGURE P10.44 Problems 44 and 45.

An object that has a small mass and an object that has a large mass have the same momentum. Which object has the largest kinetic energy?

Figure P9.59a shows an overhead view of the configuration of two pucks of mass In on frictionless ice. The pucks are tied together with a string of length 1' and negligible mass. At time t = 0, a constant force of magnitude F begins to pull to the right on the center point of the string. At time t, the moving pucks strike each other and stick together. At this time, the force has moved through a distance 4 and the pucks have attained a speed v (Fig. P9.59b). (a) What is v in terms of F, d, e, and in? (b) How much of the energy transferred into the system by work done by the force has been transformed to internal energy?

A 1.25-kg wooden block rests on a table over a large hole as in Figure P9.39. A 5.00-g bullet with an initial velocity vi is fired upward into the bottom of the block and remains in the block after the collision. The block and bullet rise to a maximum height of 22.0 cm. (a) Describe how you would find the initial velocity of the bullet using ideas you have learned in this chapter. (b) Calculate the initial velocity of the bullet from the information provided. Figure P9.39 Problems 39 and 40.

Professional Application The Moon's craters are remnants of meteorite collisions. Suppose a fairly large asteroid that has a mass of 5.001012 kg (about a kilometer across) strikes the Moon ata speed of 15.0 km/s. (a) At what speed does the Moon recoil after the perfectly inelastic collision (the mass of the Moon is 7.361022 kg) ? (b) How much kinetic energy is lost in the collision? Such an event may have been observed by medieval English monks who reported observing a red glow and subsequent haze about the Moon. (c) In October 2009, NASA crashed a rocket into the Moon, and analyzed the plume produced by the impact. (Significant amounts of water were detected.) Answer part (a) and (b) for this real-life experiment. The mass of the rocket was 2000 kg and its speed upon impact was 9000 km/h. How does the plume produced alter these results?