points At a particular instant, a stationary observer on the ground sees a package falling with speed v1 at an angle to the vertical. To a pilot flying horizontally at constant speed relative to the ground, the package appears to be falling vertically with a speed v2 at that instant. What is the speed of the pilot relative to the ground?

2.0 points At a particular instant, a stationary observer on the ground sees a package falling with speed v1 at an angle to the vertical. To a pilot flying horizontally at constant speed relative to the ground, the package appears to be falling vertically with a speed v2 at that instant. What is the speed of the pilot relative to
the ground?
1. √
v2 1 + v2
2
2. v2 − v1
3. √
v2 1 − v2
2
4. v1 + v2
5. v1 − v2
002 (part 1 of 2) 2.0 points A particle travels to the right at a constant rate of 6.2 m/s. It suddenly is given a vertical acceleration of 2.3 m/s2 for 4 s. What is its direction of travel after the
acceleration with respect to the horizontal? Answer between −180◦ and +180◦. Answer in units of ◦
003 (part 2 of 2) 2.0 points What is the speed at this time? Answer in units of m/s
004 2.0 points A particle moving at a velocity of 8.9 m/s in the positive x direction is given an accelera- tion of 5.9 m/s2 in the positive y direction for 3.7 s. What is the final speed of the particle? Answer in units of m/s
005 (part 1 of 3) 2.0 points
A particle moves in the xy plane with constant acceleration. At time zero, the particle is at x = 2 m, y = 6.5 m, and has velocity ~vo = (2.5 m/s) ı̂ + (−8.5 m/s) ̂ . The acceleration is given by ~a = (3.5 m/s2) ı̂+ (5 m/s2) ̂ . What is the x component of velocity after
1.5 s? Answer in units of m/s
006 (part 2 of 3) 2.0 points What is the y component of velocity after 1.5 s? Answer in units of m/s
007 (part 3 of 3) 2.0 points What is the magnitude of the displacement from the origin (x = 0 m, y = 0 m) after 1.5 s? Answer in units of m
008 (part 1 of 3) 2.0 points
A ball is thrown and follows the parabolic path shown. Point Q is the highest point on the path and points P and R are the same height above the ground.
Q
RP
How do the speeds of the ball at the three points compare? Air friction is negligible.
1. ‖~v Q ‖ < ‖~v
P ‖ = ‖~v
R ‖
2. ‖~v P ‖ < ‖~v
Q ‖ < ‖~v
R ‖
3. ‖~v P ‖ = ‖~v
R ‖ < ‖~v
Q ‖
4. ‖~v Q ‖ < ‖~v
R ‖ < ‖~v
P ‖
rouzbehani (mr39949) – Motion in 2D – bump – (1004) 2
5. ‖~v R ‖ < ‖~v
Q ‖ < ‖~v
P ‖
009 (part 2 of 3) 2.0 points Which diagram best indicates the direction of the acceleration, if any, on the ball at point R?
1.
2.
3.
4.
5.
6.
7.
8. The ball is in free fall and there is no acceleration at any point on its path.
9.
010 (part 3 of 3) 2.0 points Which diagram best indicates the direction of the net force, if any, on the ball at point Q?
1.
2.
3.
4.
5.
6. The ball is in free-fall and there is no acceleration at any point on its path.
7.
8.
9.
011 (part 1 of 3) 2.0 points A ball of mass 0.4 kg, initially at rest, is kicked directly toward a fence from a point 20 m away, as shown below. The velocity of the ball as it leaves the
kicker’s foot is 17 m/s at angle of 39 ◦ above the horizontal. The top of the fence is 4 m high. The ball hits nothing while in flight and air resistance is negligible. The acceleration due to gravity is 9.8 m/s2.
b
20 m
4 m
17 m /s
39 ◦
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
Determine the time it takes for the ball to reach the plane of the fence. Answer in units of s
012 (part 2 of 3) 2.0 points How far above the top of fence will the ball
pass? Consider the diameter of the ball to be negligible.
rouzbehani (mr39949) – Motion in 2D – bump – (1004) 3
Answer in units of m
013 (part 3 of 3) 2.0 points What is the vertical component of the velocity when the ball reaches the plane of the fence? Answer in units of m/s
014 2.0 points The velocity of a projectile at launch has a horizontal component vh and a vertical com- ponent vv. When the projectile is at the high- est point of its trajectory, identify the vertical and the horizontal components of its velocity and the vertical component of its acceleration. Consider air resistance to be negligible.
Vertical Horizontal Vertical Velocity Velocity Acceleration
1. vv 0 0
2. 0 vh 0
3. vv vh 0
4. 0 0 g
5. 0 vh g
015 2.0 points
A ball is thrown and follows the parabolic path shown. Air friction is negligible. Point Q is the highest point on the path. Points P and R are the same height above the ground.
Q
RP
How do the speeds of the ball at the three points compare?
1. ‖~v Q ‖ < ‖~v
R ‖ < ‖~v
P ‖
2. ‖~v R ‖ < ‖~v
Q ‖ < ‖~v
P ‖
3. ‖~v Q ‖ < ‖~v
P ‖ = ‖~v
R ‖
4. ‖~v P ‖ < ‖~v
Q ‖ < ‖~v
R ‖
5. ‖~v P ‖ = ‖~v
R ‖ < ‖~v
Q ‖
6. ‖~v P ‖ = ‖~v
R ‖ = ‖~v
Q ‖
016 2.0 points
A ball is thrown and follows the parabolic path shown. Air friction is negligible. Point Q is the highest point on the path. Points P and R are the same height above the ground.
Q
RP
Which of the following diagrams best indi- cates the direction of the acceleration, if any, on the ball at point P?
1.
2. The ball is in free-fall and there is no acceleration at any point on its path.
3.
4.
5.
rouzbehani (mr39949) – Motion in 2D – bump – (1004) 4
6.
7.
8.
9.
017 2.0 points
A ball is thrown and follows the parabolic path shown. Air friction is negligible. Point Q is the highest point on the path. Points P and R are the same height above the ground.
Q
RP
Which of the following diagrams best indi- cates the direction of the acceleration, if any, on the ball at point R?
1.
2.
3.
4.
5.
6.
7.
8. The ball is in free-fall and there is no acceleration at any point on its path.
9.
018 2.0 points
A bowling ball accidentally falls out of the cargo bay of an airliner as it flies along in a horizontal direction.
Z
Y
X
W
U
V
As observed by a person standing on the ground and viewing the plane as in the fig- ure, which path would the bowling ball most closely follow after leaving the airplane?
1. X
2. Y
3. V
4. U
5. Z
6. W
rouzbehani (mr39949) – Motion in 2D – bump – (1004) 5
019 2.0 points Aman can throw a ball a maximum horizontal distance of 169 m on a level field. The acceleration of gravity is 9.8 m/s2 . How far can he throw the same ball verti-
cally upward from the ground? (Assume that the ball is thrown from the ground and that his muscles give the ball the same speed in each case.) Answer in units of m
020 2.0 points Assume: A 78 g basketball is launched at an angle of 40.4◦ and a distance of 17.8 m from the basketball goal. The ball is released at the same height (ten feet) as the basketball goal’s height. A basketball player tries to make a long
jump-shot as described above. The acceleration of gravity is 9.8 m/s2 . What speed must the player give the ball? Answer in units of m/s
021 (part 1 of 3) 2.0 points A cannon sends a projectile towards a target a distance 1490 m away. The initial velocity makes an angle 39◦ with the horizontal. The target is hit. The acceleration of gravity is 9.8 m/s2 . What is the magnitude of the initial veloc-
ity? Answer in units of m/s
022 (part 2 of 3) 2.0 points How high is the highest point of the trajec- tory? Answer in units of m
023 (part 3 of 3) 2.0 points How long does it take for the projectile to reach the target? (Assume no friction) Answer in units of s
024 2.0 points If you are standing in a bus that moves at constant velocity and drop a ball from your outstretched hand, you will see its path as a vertical straight line.
How will the path appear to a friend stand- ing at the side of the road?
1. The path is a straight line slanted down.
2. The path is a straight line orientated vertically.
3. The path curves downward.
4. The path curves upward.
025 (part 1 of 2) 2.0 points A person can jump a horizontal distance of 2.55 m on the Earth. The acceleration of gravity is 5.91 m/s2 . How far could he jump on the Moon, where
the free-fall acceleration is 0.297g? Answer in units of m