Multiple Choice

ENGGPHYS I 7:30-9:00 I M-S Class Code: 1. A 350-9 object slides 120 cm atonga horizontal tabletop. How much work is done in overcoming friction between the object and the table it the coefficient of kinetic friction is 0.30? A. M328 J C. 1.2348 J ~ B. 1.3482J D. 1.8243 J 'V'F. to. A rocket standing on its launch platform points straight upward. Its jet engines are activated and eiect gas at the ran at too kg/second. The molecules are expelled with 3 Speed 01 6-0 km/minute. How much mass can the rocket initially have it it is slowly to rise because of the thrust of the engines? A. 10,171. kg C. 10.349 kg B. 10,204 kg D. 10,381 kg 2. A car going 20 m/s is brought to rest in a distance of 4 meters as it strikes a pile of dirt. How large an average force is exerted by the seatbelts on an 80-kg passenger as the car stopped? A. 16 KN - C. 4 KN B. 20 KN D. 8 KNCode: 3. A 1400-kg car is coasting down a 35 hill as shown. At a time when the car's speed is 15 m/s, the driver applies the brakes. What constant F (parallel to the road) must result if the car is to stop after travelling 50 meters? A. 4.7195 KN C. 4.1795 KN B. 4.9175 KN D. 4.5197 KN LO 50 m 50 sin 30Class Code: 4. A 600-g block is shot up the incline with an initial speed of 250 cm/s. How far up the incline will it go if the coefficient of kinetic friction between it and the incline is 0.10? A. 62.2192 cm C. 62.1229 cm B. 62.1292 cm D. 62.9212 cm 2502604 QUIZ 3 5. An advertisement claims that a certain 1500-kg car can accelerate from rest to a speed of 30 m/s in a time of 4.5 seconds. What average power must the motor produce to cause this acceleration? Ignore friction losses. A. 201.0724 HP C. 203.6439 HP B. 150.0000 HP D. 151.0678 HP6. In unloading gravel from the ground to the top of a mixer, an elevator lifts the gravel through a distance of 15 meters. Gravel is then discharged on the top of the mixer at a rate of 5 kg per second, and the discharge speed of each gravel particle is 4 m/s. Find the minimum horsepower that can elevate and discharge gravel in this way. A. 2.9372 HP C. 1.6091 HP B. 2.2884 HP D. 1.0389 HP2604 QUIZ 3 7. A 0.30-kg ball moving to the right at 15 m/s is hit by a bat. Its final velocity is 24 m/s directed to the left. The bat acts on the ball for 0.025 second. Find the average force exerted by the bat on the ball. A. 468 N C. 269 N B. 371 N D. 108 N"m we: a. m balls at equal mass approach the coordinate origin. on. moving downward along the +y axle at 2.5 "1/3 and the Other moving to the right along the x axls at 3.5 m/s. After they collide, one ball moves out to the ght along the 4): axis at 1.60 m/s. Find the scalar x and y velocity at the other ball. A. v, . l9 m/s and V1! : - 2.4 m/s 8. V, - 1.8 m/s and Vy = - 2.5 m/s C. V; ~19 m/s and V7 = - 2.5 m/s ' D. Vx -= 1.8 m/s and VV = - 2.4 m/s 2604 9. Two identical balls collide head-on. The initial velocity of ball QUIZ 3 1 is 4 m/s due east, while that of ball 2 is 6 m/s due west. If each ball? the collision is perfectly elastic, what is the final velocity of A. Vit = - 6 m/s and Vor = 4 m/s B. Vy = 4 m/s and V2 = - 6 m/s N C. Either A or B D. Both A and B