Vectors and Projectiles Problems MC Questions vw d vB L q vo R h x y

01 The resultant of two vectors is the smallest when the angle between the two vectors is The resultant of two vectors is the smallest when the angle between the two vectors is (A) 0°. (B) 45°. (C) 90°. (D) 180°. (A) 0° (B) 45° (C) 90° (D) 180°.

02 6) Two vectors, of magnitudes 20 and 50, are added. Which one of the following is a possible answer for the magnitude of the resultant? (A) 10 (B) 20 (C) 40 (D) 80 Answer: C Diff: 1 Type: MC Var: 1 Page Ref: Sec. 3.2-3.4 Two vectors, of magnitudes 20 and 50, are added. Which one of the following is a possible answer for the magnitude of the resultant? (A) 10 (B) 20 (C) 40 (D) 80

03 31) An airplane with a speed of 120 km/h is headed 30.0° east of north in a wind blowing due west at 30.0 km/h. What is the speed of the plane relative to the ground? (A) 90.0 km/h (B) 110 km/h (C) 137 km/h (D) 150 km/h Answer: B Diff: 2 Type: BI Var: 2 Page Ref: Sec. 3.8 An airplane with a speed of 120 km/h is headed 30.0° east of north in a wind blowing due west at 30.0 km/h. What is the speed of the plane relative to the ground? (A) 90.0 km/h (B) 110 km/h (C) 137 km/h (D) 150 km/h

04 16) An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance away? (A) 30° and 80° (B) 40° and 60° (C) 40° and 80° (D) 30° and 60° Answer: D Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance away? (A) 30° and 80° (B) 40° and 60° (C) 40° and 80° (D) 30° and 60°

05 22) A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground? (A) 100 m (B) 162 m (C) 177 m (D) 283 m Answer: A Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground? (A) 100 m (B) 162 m (C) 177 m (D) 283 m

06 24) A projectile is launched with an initial velocity of 60.0 m/s at an angle of 30.0° above the horizontal. What is the maximum height reached by the projectile? (A) 23 m (B) 46 m (C) 69 m (D) 92 m Answer: B Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A projectile is launched with an initial velocity of 60.0 m/s at an angle of 30.0° above the horizontal. What is the maximum height reached by the projectile? (A) 23 m (B) 46 m (C) 69 m (D) 92 m

07 37) A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 min 40 s. She is swept downstream 480 m. What is the speed of the current? (A) 0.50 m/s (B) 1.2 m/s (C) 1.4 m/s (D) 1.8 m/s Answer: B Diff: 3 Type: BI Var: 1 Page Ref: Sec. 3.8 A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 min 40 s. She is swept downstream 480 m. What is the speed of the current? (A) 0.50 m/s (B) 1.2 m/s (C) 1.4 m/s (D) 1.8 m/s

08 3) If you walk 6.0 km in a straight line in a direction north of east and you end up 2.0 km north and several kilometers east. How many degrees north of east have you walked? (A) 19° (B) 45° (C) 60° (D) 71° Answer: A Diff: 2 Type: BI Var: 2 Page Ref: Sec. 3.2-3.4 If you walk 6.0 km in a straight line in a direction north of east and you end up 2.0 km north and several kilometers east. How many degrees north of east have you walked? (A) 19° (B) 45° (C) 60° (D) 71°

09 20) A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown? (A) 6.1 m/s (B) 7.4 m/s (C) 8.1 m/s (D) 8.9 m/s Answer: C Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown? (A) 6.1 m/s (B) 7.4 m/s (C) 8.1 m/s (D) 8.9 m/s

10 35) The driver of a motorboat that can move at 10 m/s in still water wishes to travel directly across a narrow strait in which the current flows at 5.0 m/s. At what angle upstream should the driver head the boat? (A) 27° (B) 30° (C) 60° (D) 63° Answer: B Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.8 The driver of a motorboat that can move at 10 m/s in still water wishes to travel directly across a narrow strait in which the current flows at 5.0 m/s. At what angle upstream should the driver head the boat? (A) 27° (B) 30° (C) 60° (D) 63°

11 15) At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range? (A) 0° (B) 30° (C) 45° (D) 60° Answer: C Diff: 1 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range? (A) 0° (B) 30° (C) 45° (D) 60°

12 28) Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km downstream, in a river flowing at 6.0 km/h? (A) 20 min (B) 22 min (C) 24 min (D) 30 min Answer: A Diff: 1 Type: BI Var: 2 Page Ref: Sec. 3.8 Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km downstream, in a river flowing at 6.0 km/h? (A) 20 min (B) 22 min (C) 24 min (D) 30 min

13 13) A runner runs halfway around a circular path of radius 10 m. What is the displacement of the jogger? (A) 0 (B) 5 m (C) 10 m (D) 20 m Answer: D Diff: 1 Type: BI Var: 1 Page Ref: Sec. 3.2-3.4 A runner runs halfway around a circular path of radius 10 m. What is the displacement of the jogger? (A) 0 (B) 5 m (C) 10 m (D) 20 m

14 2) If a ball is thrown with a velocity of 25 m/s at an angle of 37° above the horizontal, what is the vertical component of the velocity? (A) 12 m/s (B) 15 m/s (C) 19 m/s (D) 25 m/s Answer: B Diff: 1 Type: BI Var: 2 Page Ref: Sec. 3.2-3.4 If a ball is thrown with a velocity of 25 m/s at an angle of 37° above the horizontal, what is the vertical component of the velocity? (A) 12 m/s (B) 15 m/s (C) 19 m/s (D) 25 m/s

15 9) A car travels 20 km west, then 20 km south. What is the magnitude of its displacement? (A) 0 km (B) 20 km (C) 28 km (D) 40 km Answer: C Diff: 1 Type: BI Var: 1 Page Ref: Sec. 3.2-3.4 A car travels 20 km west, then 20 km south. What is the magnitude of its displacement? (A) 0 km (B) 20 km (C) 28 km (D) 40 km

16 18) A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff? (A) 22 m (B) 43 m (C) 77 m (D) 91 m Answer: D Diff: 1 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff? (A) 22 m (B) 43 m (C) 77 m (D) 91 m

17 22) A jumper in the long-jump goes into the jump with a speed of 12 m/s at an angle of 20° above the horizontal. How far does the jumper jump? (A) 3.4 m (B) 6.2 m (C) 9.4 m (D) 15 m Answer: C Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A jumper in the long-jump goes into the jump with a speed of 12 m/s at an angle of 20° above the horizontal. How far does the jumper jump? (A) 3.4 m (B) 6.2 m (C) 9.4 m (D) 15 m

18 23) A projectile is launched with an initial velocity of 60.0 m/s at an angle of 30.0° above the horizontal. How far does it travel? (A) 152 m (B) 160 m (C) 184 m (D) 318 m Answer: D Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A projectile is launched with an initial velocity of 60.0 m/s at an angle of 30.0° above the horizontal. How far does it travel? (A) 152 m (B) 160 m (C) 184 m (D) 318 m

19 28) On a calm day (no wind), you can run a 1500-m race at a velocity of 4.0 m/s. If you ran the same race on a day when you had a constant headwind which slows your speed by 2.0 m/s, the time it would take you to finish would be (A) 250 s. (B) 750 s. (C) 1125 s. (D) 9000 s. Answer: B Diff: 1 Type: BI Var: 2 Page Ref: Sec. 3.8 On a calm day (no wind), you can run a 1500-m race at a velocity of 4.0 m/s. If you ran the same race on a day when you had a constant headwind which slows your speed by 2.0 m/s, the time it would take you to finish would be (A) 250 s. (B) 750 s. (C) 1125 s. (D) 9000 s.

20 19) A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water? (A) 14 m (B) 16 m (C) 20 m (D) 24 m Answer: C Diff: 2 Type: BI Var: 1 Page Ref: Sec. 3.5-3.6 A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water? (A) 14 m (B) 16 m (C) 20 m (D) 24 m

END