Previewer Tools Show All In View: Key. Hidden: Assignment Score Mark Help/Hints Solution Show New Randomization Open in Editor

Transcription

1 Assignment Previewer 151 Practice Problems Exam II (465958) About this Assignment Previewer Tools Show All In View: Key Hide All Close this window Hidden: Assignment Score Mark Help/Hints Solution Show New Randomization Open in Editor 1. CJ7 5.P.024. [565572] Show Details Interactive Solution 5.24 offers help in modeling this problem. A racetrack has the shape of an inverted cone, as the drawing shows. On this surface the cars race in circles that are parallel to the ground, and the surface is at an angle = 25. For a speed of 26 m/s, at what value of the distance d should a driver locate his car if he wishes to stay on a circular path without depending on friction? [163] m 2. CJ7 5.P.025. [565582] Show Details ssm A jet (m = kg), flying at 110 m/s, banks to make a horizontal circular turn. The radius of the turn is 3810 m. Calculate the necessary lifting force. [1.03e+06] N 3. CJ7 5.P.036. [565560] Show Details A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to six times her weight as she goes through the dip. If r = 22.0 m, how fast is the roller coaster traveling at the bottom of the dip? [32.8] m/s 4. CJ7 5.P.040. [565554] Show Details

2 A motorcycle is traveling up one side of a hill and down the other side. The crest is a circular arc with a radius of 50.0 m. Determine the maximum speed that the cycle can have while moving over the crest without losing contact with the road. [22.1] m/s 5. CJ7 6.P.077. [568621] Show Details ssm A water slide is constructed so that swimmers, starting from rest at the top of the slide, leave the end of the slide traveling horizontally. As the drawing shows, one person hits the water 5.00 m from the end of the slide in a time of s after leaving the slide. Ignoring friction and air resistance, find the height H in the drawing. [6.18] m 6. CJ7 6.P.047. [568655] Show Details ssm A roller coaster (305 kg) moves from A (5.00 m above the ground) to B (23.0 m above the ground). Two nonconservative forces are present: friction does J of work on the car, and a chain mechanism does J of work to help the car up a long climb. What is the change in the car's kinetic energy, KE = KE f - KE 0, from A to B? [-43800] J 7. CJ7 6.P.051. [568631] Show Details Interactive Solution 6.51 offers help in modeling this problem. A 52.0 kg person jumps from rest off a 12.0 m high tower straight down into the water. Neglect air resistance during the descent. She comes to rest 3.00 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This force is nonconservative. [2550] N 8. CJ7 6.P.052. [568659] Show Details A pitcher throws a kg baseball, and it approaches the bat at a speed of 40.0 m/s. The bat does W nc = 65.0 J of work on the ball in hitting it. Ignoring air resistance, determine the speed of the ball after the ball leaves the bat and is 25.0 m above the point of impact.

3 [45.2] m/s 9. CJ7 6.P.065. [568620] Show Details The graph shows the net external force component F cos along the displacement as a function of the magnitude of the displacement s. The graph applies to a 64 kg ice skater. (a) How much work does the net force component do on the skater from 0 to 3.0 m? [93] J (b) How much work does the net force component do on the skater from 3.0 m to 6.0 m? [0] J (c) If the initial speed of the skater is 2.3 m/s when s = 0, what is the speed when s = 6.0 m? [2.86] m/s 10. CJ7 6.P.066. [568622] Show Details The graph shows how the force component F cos along the displacement varies with the magnitude s of the displacement. If F max = 57.5 N and s max = 1.40 m, find the work done by the force. (Hint: Recall how the area of a triangle is related to the triangle's base and height.) [40.2] J 11. CJ7 6.P.070. [568629] Show Details

4 A projectile of mass kg is shot straight up with an initial speed of 14.0 m/s. (a) How high would it go if there were no air friction? [10] m (b) If the projectile rises to a maximum height of only 5.8 m, determine the magnitude of the average force due to air resistance. [6.39] N 12. CJ7 6.P.071. [568652] Show Details ssm Suppose in Figure 6.2 that J of work are down by the force F (magnitude = 30.0 N) in moving the suitcase a distance of 47.0 m. At what angle, counterclockwise from the x-axis, is the force oriented with respect to the ground? [38.7] 13. CJ7 6.P.076. [568651] Show Details A 63 kg skier coasts up a snow-covered hill that makes an angle of 25 with the horizontal. The initial speed of the skier is 6.7 m/s. After coasting a distance of 1.9 m up the slope, the speed of the skier is 3.0 m/s. (a) Find the work done by the kinetic frictional force that acts on the skiis. [-635] J (b) What is the magnitude of the kinetic frictional force? [334] N 14. CJ7 7.P.053. [568700] Show Details ssm By accident, a large plate is dropped and breaks into three pieces. The pieces fly apart

5 parallel to the floor, with v 1 = 2.80 m/s and v 2 = 1.95 m/s. As the plate falls, its momentum has only a vertical component, and no component parallel to the floor. After the collision, the component of the total momentum parallel to the floor must remain zero, since the net external force acting on the plate has no component parallel to the floor. Using the data shown in the drawing, find the masses of pieces 1 and 2. m 1 = [1.07] kg m 2 = [0.92] kg 15. CJ7 7.P.054. [568706] Show Details A person stands in a stationary canoe and throws a 4.96 kg stone with a velocity of 7.60 m/s at an angle of 32.0 above the horizontal. The person and canoe have a combined mass of 105 kg. Ignoring air resistance and effects of the water, find the horizontal recoil velocity (magnitude and direction) of the canoe. magnitude direction [0.304] m/s ---Select--- horizontal component of the velocity of the stone ] [ opposite the 16. CJ7 7.P.049. [609068] Show Details In a football game, a receiver is standing still, having just caught a pass. Before he can move, a tackler, running at a velocity of +4.3 m/s, grabs him. The tackler holds onto the receiver, and the two move off together with a velocity of +2.9 m/s. The mass of the tackler is 125 kg. Assuming that momentum is conserved, find the mass of the receiver.

6 [60.3] kg 17. CJ7 7.P.047. [568680] Show Details ssm A 5.00 kg ball (ball 1), moving to the right at a velocity of m/s on a frictionless table, collides head-on with a stationary 7.70 kg ball (ball 2). Find the final velocities of the balls if the collision is as specified below. (a) elastic collision ball 1 ball 2 (b) completely inelastic collision ball 1 ball 2 [-0.85] m/s [3.15] m/s [1.57] m/s [1.57] m/s 18. CJ7 7.P.046. [598535] Show Details A car (mass = 1100 kg) is traveling at 41 m/s when it collides head-on with a sport utility vehicle (mass = 2330 kg) traveling in the opposite direction. In the collision, the two vehicles come to a halt. At what speed was the sport utility vehicle traveling? [19.4] m/s 19. CJ7 7.P.024. [568672] Show Details A wagon is coasting at a speed v a along a straight and level road. When 16 percent of the wagon's mass is thrown off the wagon, parallel to the ground and in the forward direction, the wagon is brought to a halt. If the direction in which this mass is thrown is exactly reversed, but the speed of this mass relative to the wagon remains the same, the wagon accelerates to a new speed v b. Calculate the ratio v b / v a. [2] 20. CJ7 7.P.029. [568683] Show Details A 2.50 g bullet, traveling at a speed of 395 m/s, strikes the wooden block of a ballistic pendulum, as shown. The block has a mass of 265 g.

7 (a) Find the speed of the bullet/block combination immediately after the collision. [3.69] m/s (b) How high does the combination rise above its initial position? [0.695] m 21. CJ7 7.P.030. [568713] Show Details The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of kg and is initially at rest. The collision is not head-on. After the collision, the two pucks fly apart with the angles shown in the drawing.

8 (a) Find the final speed of puck A. [3.38] m/s (b) Find the final speed of puck B. [3.02] m/s 22. CJ7 7.P.031. [568687] Show Details ssm Batman (mass = 106 kg) jumps straight down from a bridge into a boat (mass = 570 kg) in which a criminal is fleeing. The velocity of the boat is initially +17 m/s. What is the velocity of the boat after Batman lands in it? [14.3] m/s 23. CJ7 7.P.003. [568711] Show Details A golfer, driving a golf ball off the tee, gives the ball a velocity of +39 m/s. The mass of the ball is kg, and the duration of the impact with the golf club is s. (a) What is the change in momentum of the ball? [1.75] kg m/s (b) Determine the average force applied to the ball by the club. [494] N Submit for Testing Assignment Details: ( Hide ) Name (AID) 151 Practice Problems Exam II (465958) Submissions Allowed 1

9 Category Code Locked Exam No Author Leilabady, Dr. Pedram ( pleilaba@ .uncc.edu ) Last Saved Permission Randomization Which graded Mar 21, :41 PM EDT Protected Person Last Feedback: Detailed grade with resubmit allowed Before due date After due date Save Work Response Response Assignment Score Assignment Score Question Score Question Score Question Part Score Question Part Score Mark Mark Publish Essay Scores Publish Essay Scores Help/Hints Help/Hints Key