2-D Kinematics 4
1. A car travels due east at 20 m/s. It makes a turn due south and continues to travel at 20 m/s. What
is the change in velocity of the car?
A) 20 m/s, due east D) 28 m/s, 45? south of east
B) 20 m/s, due south E) zero m/s
C) 28 m/s, 45? south of west
2. A train travels due south at 60 m/s. It reverses its direction and travels due north at 60 m/s. What is
the change in velocity of the train?
A) 120 m/s, due north D) 60 m/s, due south
B) 120 m/s, due south E) 0 m/s
C) 60 m/s, due north
Use the following to answer questions 3-6:
A small boat travels 80.0 km north and then travels 60.0 km east in 1.0 hour.
3. What is the boat's displacement for the one-hour trip?
A) 20 km B) 100 km C) 140 km D) 280 km E) 10 000 km
4. What is the boat's average speed during the one-hour trip?
A) 20 km/h B) 100 km/h C) 140 km/h D) 280 km/h E) 10 000 km/h
5. What is the magnitude of the boat's average velocity for the one-hour trip?
A) 20 km/h B) 100 km/h C) 140 km/h D) 10 000 km/h E) 20 000 km/h
6. What is the direction of the boat's average velocity for the one-hour trip?
A) due east D) 49.2? north of east
B) 36.9? north of east E) 53.1? north of east
C) 41.7? north of east
7. A ferry can travel at an optimal speed of 8 km/h in still water measured relative to the shore. What
is the optimal speed of the ferry, relative to the shore, if it moves perpendicular to a 6 km/h current?
A) 4 km/h B) 8 km/h C) 10 km/h D) 14 km/h E) 28 km/h
8. A boat that can travel at 4.0 km/h in still water crosses a river with a current of 2.0 km/h. At what
angle must the boat be pointed upstream (that is, relative to its actual path) to go straight across
A) 27? B) 30? C) 60? D) 63? E) 90?
Use the following to answer questions 9-10:
A man points his rowboat north from A to B, straight across a river of width 100 m. The river flows due east. The man starts across, rowing steadily at 0.75 m/s and reaches the other side of the river at point C,
150 m downstream from his starting point.
9. What is the speed of the river?
A) 0.38 m/s B) 0.67 m/s C) 1.1 m/s D) 6.7 m/s E) 7.5 m/s
10. While the man is crossing the river, what is his velocity relative to the shore?
A) 1.35 m/s, 34? north of east D) 2.11 m/s, 34? north of east B) 2.00 m/s, 56?north of east E) 2.50 m/s, 42? north of east
C) 1.74 m/s, 34? north of east
A toolbox is carried from the base of a ladder at point A as shown in the figure. The toolbox
comes to a rest on a scaffold 5.0 m above the ground. What is the magnitude of the
displacement of the toolbox in its movement from point A to point B?
A) 15 m
B) 19 m
C) 8.1 m
D) 11 m
E) 13 m
The vector equation that describes the relationship among vectors A, B, and C is
A) B = C + A B) B = C – A C) C = A – B D) A = B – C E) A = B + C