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Instructor: Hai-Ping Cheng TA: Rashid Hamdan PHYSICS DEPARTMENT PHY 2004 Exam 2 March 15, 2013 Name (print, last first): Signature: On my honor, I have neither given nor received unauthorized aid on this examination. YOUR TEST NUMBER IS THE 5-DIGIT NUMBER AT THE TOP OF EACH PAGE. DIRECTIONS Fist answer is the correct answer 1- A 1000 Kg car has a motor that deliver 12 kWatt to move the car forward. The maximum speed of the car on a horizontal road is 20 m/s. How large is the retarding force acting on the car at that speed?(in Newtons) a) 600 b) 1200 c) 120 d) 6000 e) 800 2- A pendulum is 40 cm long. It is pulled aside by an angle 60 degree. Find the speed of the pendulum as the ball goes through the lowest point. How high above its lowest position will the pendulum swing on the other side? Ignore friction. a) 2.0 m/s, 20 cm b) 4.0 m/s, 20 cm c) 4.0 m/s, 40 cm d) 2.0 m/s, 40 cm e) 3.0 m/s, 30 cm 3- A 10 g bullet moving at 600 m/s, hits a 5 kg wood block resting on the table. The bullet sticks in the wood. How fast is the block sliding across the table just after the collision? (m/s) a) 1.2 b) 2.0 c) 0.6 d) 2.4 e) 3.1 4- Two Identical billiard balls (A) and (B) are approaching each other head-on. (A) has a velocity 2.0 m/s, whereas (B) has a velocity - 4.0 m/s. If the collision is perfectly elastic, what is the velocity of (A) right after the collision? (m/s) a) – 4 b) 8 c) 6 d) 4 e) -6 5- A block of mass 2 kg slides on an incline starting from rest. When the block reaches a point 30 cm below it original height its speed is 1.2 m/s. If the distance covered on the plane is 120 cm, what is the friction on the block? (N) a) 3.7 b) 4.8 c) 12.2 d) 1.2 e) 2.5 6. Find the IMA of the pulley system in the figure by considering distance si and so. si/so=? (a) (b) (c) (d) (e) 4 2 5 3 6 W 7. A 40-N object is to be lifted by a machine using a force 20 N. Measurments on distance finds that the object moves 1.2 m when the applied force moves 24 m. Find the IMA, AMA and efficiency. (a) 20, 2, 10% (b) 0.05, 0.5, 10% (c) 0.05, 0.5, 10 (d) 20, 2, 1 (e) 2, 20, 10% 8. If a string can hold up to a 1000 N force, what is the maximun velocity a 200-g mass to be spung in a horizontal circle of 0.5 m (in m/s) (a) 50 (b) 2500 (c) 25 (d) 5000 (e) 3000 9. After the power is turned off to a motor whose shaft speed is 240 rev/min, the motor takes 2 s to stop. Through how many revolution did the shaft turn while the motor came to rest? Assume uniform acceleration (deceleration). (in rev) (a) 4 (b) 8 (c) 64 (d) 2 (e) 16