University:
Missouri State University
Course:
PHY 203 | Foundations of Physics I
Academic year:

2019
Views:

376

Pages:

2
Author:

Derrick Hunt

24-A400 AF FA 19. A 24-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface. Ifthe coefficients of friction are mu_{s} = 0.5 and mu_{k} =0.4 k the magnitude of the frictional force on the block is: A) 8N B) 12 N C) 16 N D) 20 N E) 400 N F f 5 (ma,s)=m 5 F n = (0.5)(40) = 2N H_{k} = mu_{k} = (0.4)(40) = 16N So it slides) 20. A car is traveling at 15 m/s on a horizontal road. The brakes are applied and the car skids to a stop in 4.0 s. The corticiant of kinetic friction between the tires and road is: v_{1} > 15 v_{t} = 0 t = 4 A) 0.38 B) 0.69 C) 0.76 D) 0.92 E) 1.11 ) oons tool a_{6} = 3/g = 0, 383 omega = v_{f} = w_{i} + ct O = Is*tau*a(4) 15 21. The coefficient of kinetic friction: A) is in the direction of the frictional force B) is in the direction of the normal force C) is the ratio of force to area D) is the ratio of friction force to normal force E) has units of newtons 22. Why do raindrops fall with constant speed during the later stages of their descent? A) The gravitational force is the same for all drops B) Air resistance just balances the force of gravity C) The drops all fall from the same height D) The force of gravity is negligible for objects as small as raindrops E) Gravity cannot increase the speed of a falling object to more than 32 ft/s end of their fall, their velocities are equal because: 7. Two objects, one having three times the mass of the other, are dropped from the same height in a vacuum. At the A) anything falling in vacuum has constant velocity B) all objects reach the same terminal velocity D) the force of gravity is the same for both objects C) the acceleration of the larger object is three times greater than that of the smaller object E) none of the above 8. The block shown moves with constant velocity on a horizontal surface. Two of the forces on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is: EF=0 3N 5N (a=-g A) 0 B) 2 N, leftward C) 2 N, rightward D) slightly more than 2 N, leftward E) slightly less than 2 N, leftward 9. Equal forces Fact on isolated bodies A and B. The mass of B is three times that of A. The magnitude of the acceleration of A is: A three times that of B B) 1/3 that of B C) the same as B D) nine times that of B E) 1/9 that of B 10. A car travels east at constant velocity. The net force on the car is: A) east B) west C) up D) down Ezero 11. A 6-kg object is moving south. A net force of 12 N north on it result in the object having an acceleration of: -A) - 2m / (s ^ 2) . north B 2m / s * t_{s} south 6 north D) 18m / (s ^ 2) north E) 18m / (s ^ 3) south az? 12. A 1000-kg elevator is rising and its speed is increasing at 3m / (s ^ 2) The tension in the elevator cable is: F_{7} = A) 6800 N B) 1000 N C) 3000 N D) 9800 N E) 12800 N Page 2 F_{T} = ma + my = m(ab) = 1000 (3+9.8) =12 N A Sigma*F = ma G = (Sigma*F)/M a = 5sqrt^2 5 * f F_{T} - F_{L} = ma a = (- d * q)/(gamma ^ 2) Q = (- F_{5})/m a = (2F)/m = 12/6