INTI INTERNATIONAL UNIVERSITY FOUNDATION IN SCIENCE (CFSI) PHY1203: GENERAL PHYSICS 1 FINAL EXAMINATION: SEPTEMBER 2012 SESSION PHY1203(F)/Page 1 of 5 Instructions: This paper consists of FIVE (5) questions. Answer any FOUR (4) questions in the answer booklet provided. All questions carry equal marks. Question 1 The diameter of the Moon is 3480 km. Assume the Moon is in sphere, calculate the volume of the Moon. The position of the particle is given by (t) = (t 3 3t 2 + 6) m, where t is time in s. Determine the velocity of the particle at t = 4 s, and the average velocity of the particle between t = 2 s and t = 4 s. A rock is thrown vertically upward with a speed of 12.0 m/s. Exactly 1.00 s later, a ball is thrown up vertically along the same path with a speed of 18.0 m/s. At what time will they strike each other? Two vectors are given as: and. Determine,,, and (iv) the angle between
PHY1203(F)/Page 2 of 5 Question 2 An object is projected horizontally from a platform 2.30 m above ground level. It lands on the ground at A which is 7.60 m from the platform as shown in Figure Q2. v o 2.30 m 7.60 m A Calculate the time of the object s flight. Figure Q2 Calculate the initial velocity of the object. Calculate the magnitude of the velocity of the ball just before it reaches the ground. Figure Q2 shows three boxes connected by cords, one of which wraps over a pulley having negligible friction on its axle and negligible mass. The mass of the boxes are m A = 5 kg, m B = 3 kg, and m C = 4 kg. When the system is released from rest, determine a a B A C Figure Q2 the acceleration of the system, the tension in the cord connecting A and B, and (6 marks) the tension in the cord connecting B and C.
PHY1203(F)/Page 3 of 5 A particle is rounding a fix point at a constant speed of 8.3 m/s making a uniform circular motion in a path of radius 3.0 m from the fix point. Calculate the centripetal acceleration of the motion, and period of the motion. Question 3 A 7.5 kg mass rests on a horizontal plane as shown in Figure Q3. Between the mass and the surface of the plane, the coefficient of static friction, μ s is 0.50 and the coefficient of kinetic friction, μ k is 0.36. A constant horizontal force of 35 N and a constant vertical force of P are acting on the mass. P 7.5 kg 35 N Figure Q3 Calculate the minimum magnitude of force P that will just start the motion. Calculate the acceleration of the mass if P = 10 N. Two glass marbles are moving along a straight line coming toward each other until undergo a complete elastic collision. The speed of one marble is 10 m/s and its mass is 13 g, the speed of the other marble is 8 m/s and its mass is 15 g. Determine the speeds and directions of the marbles after the collision. (6 marks) A 920 kg sports car collides into the rear end of a 2300 kg SUV stopped at a red light. The bumpers lock, the brakes are locked and the two cars skid forward 2.8 m before stopping. The police officer calculates the speed of the sports car at impact and estimating the coefficient of kinetic friction between tires and the road to be 0.8. What was that speed? A car with a mass of 2200 kg is moving with a speed of 110 km/h. Given that 30% of the car s kinetic energy lost when the driver press the brake of the car. Calculate its final speed.
(e) PHY1203(F)/Page 4 of 5 The spring used in a projectile launcher has a spring constant of 535 N/m. When the spring is compressed 5.0 cm, a 400 g ball is placed into the launcher. Calculate the speed of the ball just before it was shot out of the launcher. Question 4 A small rubber wheel is used to drive a large pottery wheel. The two wheels are mounted so that their circular edge touch. The small wheel has a radius of 2.0 cm and accelerates at the rate of 7.2 rad/s 2, and it is in contact with the pottery wheel (radius 21.0 cm) without slipping. Calculate the angular acceleration of the pottery wheel, and the time it takes the pottery wheel to reach its required speed of 65 rpm. A thin, hollow 0.545 kg section of pipe (I = mr 2 ) with radius 10.0 cm starts rolling (from rest) down a 17.5 incline for 5.6 m long. If the pipe rolls without slipping, calculate its speed at the base of the incline. Determine its total kinetic energy at the base of the incline. (e) A potter s wheel is rotating around a vertical axis through its center at a frequency of 1.5 rev/s. The wheel can be considered a uniform disk of mass 5.0 kg and diameter 0.40 m. The potter then throws a 2.6 kg chunk of clay, approximately shaped as a flat disk of radius 8.0 cm, onto the center of the rotating wheel. Determine the frequency of the wheel after the clay stick to it? [Moment of inertia of disk, I = mr 2 ] Given that the acceleration of gravity at the surface of Mars is 0.38 of what it is on Earth, and that Mars radius is 3400 km. Determine the mass of Mars. (Given that the mass of the Earth = 5.98 10 24 kg, radius of the Earth = 6380 km) A scuba diver and her gear displace a volume of 65.0 L and have a total mass of 68.0 kg. What is the buoyant force on the diver in seawater? (Density of the water is 1.025 x 10 3 kg/m 3 )
PHY1203(F)/Page 5 of 5 Question 5 A tuning fork oscillates at a frequency of 441 Hz and the tip of each prong moves 1.5 mm to either side of center. Calculate the maximum speed, and the maximum acceleration of the tip of a prong. The displacement of a standing wave on a string is given by D = 2.4 sin (0.6x) cos (42t), where x and D are in centimeters and t is in seconds. Determine is the distance (cm) between nodes. Give the amplitude, frequency, and speed of each of the component waves. Find the speed of a particle of the string at x = 3.20 cm when t = 2.5 s A bat at rest sends out ultrasonic sound waves at 55.00 khz and receives them returned from an object moving directly away from it at 25.0 m/s. Calculate the received sound frequency. A stoppered test tube traps 20.0 cm 3 of air at a pressure of 1.00 atm and temperature of 21 C. The cylindrically shaped stopper at the test tube s mouth has diameter of 1.5 cm and will pop off the test tube if a net upward force of 15.0 N is applied to it. To what temperature would one have to heat the trapped air in order to pop off the stopper? Assume the air surrounding the test tube is always at a pressure of 1.00 atm. --THE END-- PHY1203(F)/SEP2012/LCY/221112