Vietnam National University - Hcmc

THE INTERNATIONAL UNIVERSITY (IU) VIETNAM NATIONAL UNIVERSITY - HCMC ASSIGNMENT SUBJECT: PHYSICS 1 GROUP: 7 – 10 STUDENTS (To submit the 19th MAY 2014) Student Name:______Student ID:______

1/ (30 pts) An air-track glider of mass 0.100 kg is attached to the end of a horizontal air track by a spring with force constant 20.0 N/m. Initially the spring is unstretched and the glider is moving at 1.50 m/s to the right. Find the maximum distance d that the glider moves to the right (a) if the air track is turned on so that there is no friction

(b) if the air is turned off so that there is kinetic friction with coefficient k = 0.47. 2/ (30 pts) An elevator has mass 600 kg, not including passengers. The elevator is designed to ascend, at constant speed, a vertical distance of 20.0 m in 16.0 s, and it is driven by a motor that can provide up to 40 hp to the elevator. What is the maximum number of passengers that can ride in the elevator? Assume that an average passenger has mass 65.0 kg. 3/ (20 pts) Two cars, both of mass m, collide and stick together. Prior to the collision, one car had been traveling north at speed 2v, while the second was traveling at speed v at an angle φ south of east (as indicated in the figure 1). Find the magnitude and direction of the velocity of the two-car system immediately after the collision. 4/ (20 pts) A uniform rod of length l and mass M rests on a smooth horizontal Figure 1 table. A point mass m = M/2 moving at right angle to the rod with speed v collides with one end of the rod and sticks to its. The moment of inertia of the rod about its center of mass is Ml2/12. (a) Describe the subsequent motion of the rod. (b) Derive the velocity (speed and direction) of the centre of mass of the combined rod and mass m after the collision. (c) Derive the angular speed of the combined rod and mass m after the collision. (d) Find the point on the rod that is stationary immediately after the collision. The end