1- A vacationer of mass 75 kg is standing on a stationary raft of mass 55 kg. The vacationer then walks towards one end of the raft at a speed of 2.3 m/s relative to the water. What are the magnitude and direction of the resulting velocity of the raft relative to the water? 2- 2 atomes of mass 2 amu (Hydrogen) and of mass 4 amu (Helium) collide in an elastic collision if the 2 amu mass is at an initial velocity of 3000 m/s [fwd] and the 4 amu atom is at an initial velocity of 2000 m/s [fwd] . Find the velocity of both atoms after the collision. 3- A 456-kg in circular orbit around Earth has a speed of 3.9 km/s and is 2.5 107 m from Earth's centre . a- Determine the magnitude and direction of the acceleration of the satellite. b- Determine the magnitude and direction of the gravitational force on the satellite. 4- A 4 104 N truck moving west at a velocity of 8 m/s collides with a 3104 N truck heading south at a velocity of 5 m/s . If these two vehicles lock together upon impact, what is their velocity? (5 m/s 25 S of W) 6- The maximum energy of a mass-spring system undergoing SHM is 5.64 J. The mass is 0.128 kg and the force constant is 244 N/m. a- What is the amplitude of the vibration? b- Find the speed of the mass when it is 15.5 cm from the equilibrium position. 7- A 0.2 kg ball attached to a vertical to a vertical spring of force constant 28 N/m is released from rest from the unstretched equilibrium position of the spring. determine how far the ball falls, under negligible air resistance, before being brought to a momentary stop by the spring