Homework Problem 75 (page 192) Calculate the force exerted on a rocket when the propelling gases are being expelled at a rate of 1150 kg/s with a speed of 4.0x104 m/s. Example: A 50 kg boy and a 35 kg girl, both wearing skates, face each other at rest. The girl pushed the boy, sending him eastward with a speed of 4 m/s. Describe the subsequent motion of the girl. (neglect friction) Example 7-5 (page 176): Calculate the recoil velocity of a 5.0 kg rifle that shoots a 0.020 kg bullet at a speed of 620 m/s. Example An object of mass M suddenly explodes into two pieces. The first piece with mass (1/3)M shoots out in the +x axis with speed 3 m/s. What is the magnitude and direction of the second piece? Example: A truck having 3500 kg is traveling east with 10 m/s. A small car having mass 1200 kg is traveling west with 20 m/s. They collide head-on with each other and stick together after collision. \\ What is the velocity of the combined unit just after the collision? Example 79 (page 181): An object of mass m is fired into a large block of mass M, which is suspended like a pendulum. As a result of the collision, the pendulum and the object stick together and swing up to a maximum height h. Calculate the initial speed of the object. Example: (similar to homework, problem #11) A 2.7 kg block of wood sits on a frictionless table. A 3.0 g bullet, fired horizontally at a speed of 500 m/s, goes completely through the block, emerging at a speed of 220 m/s. What is the speed of the block immediately after the bullet exits? Example: A big ball having 4.0 kg moves to the right with speed 3.0 m/s. A small ball having 1.0 kg moves to the left with speed 2.0 m/s. If two balls collide elastically, what are the velocities after collision