Question 1

Three vectors,   ,   , and   have the following x and y components:   The magnitude of the resultant of   ,   , and   is

Accepted Answer

A)  3.3. 
B)  5.0. 
C)  11. 
D)  7.8. 
E)  14. 
A)  3.3. 
B)  5.0. 
C)  11. 
D)  7.8. 
E)  14.

Question 2

When a particle moves in a circle with constant speed, its acceleration is

Accepted Answer

A)  constantly increasing. 
B)  constant in direction. 
C)  zero. 
D)  constant in magnitude. 
E)  constant in magnitude and direction. 
A)  constantly increasing. 
B)  constant in direction. 
C)  zero. 
D)  constant in magnitude. 
E)  constant in magnitude and direction.

Question 3

Mark throws a ball to Daniel with an initial speed of 20 m/s at an angle of 45 degrees. If they are initially 55 m apart, calculate the average speed Daniel has to run to catch the ball. Assume the ball is thrown and caught at the same height. Also assume that Daniel starts to run when the ball is thrown.)

Accepted Answer

A)  19 m/s 
B)  14 m/s 
C)  4.9 m/s 
D)  9.1 m/s 
E)  2.9 m/s 
A)  19 m/s 
B)  14 m/s 
C)  4.9 m/s 
D)  9.1 m/s 
E)  2.9 m/s

Question 4

If you ignore air resistance in projectile motion, the ________ of the projectile remains constant.

Accepted Answer

A)  velocity vector 
B)  horizontal component of the velocity vector 
C)  vertical component of the velocity vector 
D)  speed 
E)  range 
A)  velocity vector 
B)  horizontal component of the velocity vector 
C)  vertical component of the velocity vector 
D)  speed 
E)  range

Question 5

The angle between vectors   and   is 30º, and   . Which vector diagram correctly describes the vectors   ,   and   ?

Accepted Answer

A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  5) 
A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  5)

Question 6

Three vectors,   ,   , and   have the following x and y components:   The angle that the resultant makes with the positive direction of the x axis is

Accepted Answer

A)  1.2º. 
B)  36º. 
C)  50º. 
D)  40º. 
E)  70º. 
A)  1.2º. 
B)  36º. 
C)  50º. 
D)  40º. 
E)  70º.

Question 7

A car going around a curve of radius R at a speed V experiences a centripetal acceleration ac. What should be the radius of the path that leads to twice the centripetal acceleration while it travels at the same speed V?

Accepted Answer

A)  R  
B)  2R  
C)  4R  
D)  ½ R  
E)  ¼ R 
A)  R  
B)  2R  
C)  4R  
D)  ½ R  
E)  ¼ R

Question 8

Vectors   ,   ,   , and   have the following components:   The magnitude of the resultant is

Accepted Answer

A)  - 4.6 units. 
B)  5.4 units. 
C)  29 units. 
D)  3.5 units. 
E)  7.3 units. 
A)  - 4.6 units. 
B)  5.4 units. 
C)  29 units. 
D)  3.5 units. 
E)  7.3 units.

Question 9

A vector of magnitude 5 points in the +y direction. Another vector of magnitude 4 is subtracted from the first vector. The smallest possible magnitude of the sum is

Accepted Answer

A)  1. 
B)  4. 
C)  5. 
D)  9. 
E)  10. 
A)  1. 
B)  4. 
C)  5. 
D)  9. 
E)  10.

Question 10

The position vector of an object is given by   and 4 s later, its position vector is   . The units are in m. The magnitude of the change in the position vector   is

Accepted Answer

A)  0 m. 
B)    m. 
C)    m. 
D)  10 m. 
E)    m. 
A)  0 m. 
B)    m. 
C)    m. 
D)  10 m. 
E)    m.

Question 11

Vectors   and   have the following components:   The angle between the negative x axis and the vector   is

Accepted Answer

A)  -45º. 
B)  194º. 
C)  37º. 
D)  -54º. 
E)  86º. 
A)  -45º. 
B)  194º. 
C)  37º. 
D)  -54º. 
E)  86º.

Question 12

A projectile is fired at an angle of 45° above the horizontal.   If air resistance is neglected, the line in the graph that best represents the horizontal displacement of the projectile as a function of travel time is

Accepted Answer

A)  1. 
B)  2. 
C)  3. 
D)  4. 
E)  None of these is correct. 
A)  1. 
B)  2. 
C)  3. 
D)  4. 
E)  None of these is correct.

Question 13

The figure represents the parabolic trajectory of a ball going from a to e in Earth gravity but without air resistance. The initial velocity of the ball is Vo at an angle $\theta$ to the horizon. The vertical dashed lines represent equal time interval, $\Delta$t.   The horizontal velocity at point c is

Accepted Answer

A)  0. 
B)  Vo cos $\theta$). 
C)  Vo sin $\theta$). 
D)  Vo. 
E)  depends on what g is along the path. 
A)  0. 
B)  Vo cos $\theta$). 
C)  Vo sin $\theta$). 
D)  Vo. 
E)  depends on what g is along the path.

Question 14

The curve shows the position of an object with time. The object moves with a constant speed, v.   Which of the vector diagrams below best represent the change in velocity vector from P1 to P2?

Accepted Answer

A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  None of these is correct. 
A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  None of these is correct.

Question 15

A naughty squirrel jumps from a tree limb onto a birdfeeder. The tree limb is 4.5 m above the ground and the top of the bird feeder is 1.5 m above the ground. If the squirrel jumps horizontally with a velocity of 2.5 m/s, then how far away in the horizontal direction can the bird feeder be for the squirrel to just make it onto the top of the feeder.

Accepted Answer

A)  3.6 m 
B)  2.0 m 
C)  2.4 m 
D)  1.5 m 
E)  1.4 m 
A)  3.6 m 
B)  2.0 m 
C)  2.4 m 
D)  1.5 m 
E)  1.4 m

Question 16

If air resistance is neglected and the initial speed of a projectile is halved, its range

Accepted Answer

A)  doubles. 
B)  decreases by one-half. 
C)  increases by a factor of four. 
D)  decreases by a factor of four. 
E)  does not change. 
A)  doubles. 
B)  decreases by one-half. 
C)  increases by a factor of four. 
D)  decreases by a factor of four. 
E)  does not change.

Question 17

Vectors   and   have the following components:   The magnitude of the vector   is

Accepted Answer

A)  6.3 units. 
B)  10.0 units. 
C)  2.8 units. 
D)  8.2 units. 
E)  16 units. 
A)  6.3 units. 
B)  10.0 units. 
C)  2.8 units. 
D)  8.2 units. 
E)  16 units.

Question 18

The components of four vectors are as follows:   The angle that the resultant vector makes with the positive x-axis is

Accepted Answer

A)  -40º. 
B)  59º. 
C)  -49.5º. 
D)  37º. 
E)  -23º. 
A)  -40º. 
B)  59º. 
C)  -49.5º. 
D)  37º. 
E)  -23º.

Question 19

A projectile was fired at 35º above the horizontal. At the highest point in its trajectory its speed was 200 m/s. If air resistance is ignored, the initial velocity had a horizontal component of

Accepted Answer

A)  zero. 
B)  200 cos 35º) m/s. 
C)  200 sin 35º) m/s. 
D)  200/cos 35º) m/s. 
E)  200 m/s. 
A)  zero. 
B)  200 cos 35º) m/s. 
C)  200 sin 35º) m/s. 
D)  200/cos 35º) m/s. 
E)  200 m/s.

Question 20

The curve shows the position of an object with time. The object moves with a constant speed, v.   Which of the vector diagrams below best represent the velocity vector at P1 and P2?

Accepted Answer

A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  None of these is correct. 
A)  1) 
B)  2) 
C)  3) 
D)  4) 
E)  None of these is correct.

Exam 3: Motion in Two and Three Dimensions

Three vectors, , , and have the following x and y components: The magnitude of the resultant of , , and is

When a particle moves in a circle with constant speed, its acceleration is

If you ignore air resistance in projectile motion, the ________ of the projectile remains constant.

The angle between vectors and is 30º, and . Which vector diagram correctly describes the vectors , and ?

Three vectors, , , and have the following x and y components: The angle that the resultant makes with the positive direction of the x axis is

A car going around a curve of radius R at a speed V experiences a centripetal acceleration ac. What should be the radius of the path that leads to twice the centripetal acceleration while it travels at the same speed V?

Vectors , , , and have the following components: The magnitude of the resultant is

A vector of magnitude 5 points in the +y direction. Another vector of magnitude 4 is subtracted from the first vector. The smallest possible magnitude of the sum is

The position vector of an object is given by and 4 s later, its position vector is . The units are in m. The magnitude of the change in the position vector is

Vectors and have the following components: The angle between the negative x axis and the vector is

A projectile is fired at an angle of 45° above the horizontal. If air resistance is neglected, the line in the graph that best represents the horizontal displacement of the projectile as a function of travel time is

The curve shows the position of an object with time. The object moves with a constant speed, v. Which of the vector diagrams below best represent the change in velocity vector from P1 to P2?

If air resistance is neglected and the initial speed of a projectile is halved, its range

Vectors and have the following components: The magnitude of the vector is

The components of four vectors are as follows: The angle that the resultant vector makes with the positive x-axis is

A projectile was fired at 35º above the horizontal. At the highest point in its trajectory its speed was 200 m/s. If air resistance is ignored, the initial velocity had a horizontal component of

The curve shows the position of an object with time. The object moves with a constant speed, v. Which of the vector diagrams below best represent the velocity vector at P1 and P2?

Introduction to Physics

Linear Motion

Forces and Motion I: Newtons Laws

Forces and Motion II: Applications

Work and Energy

Momentum, Collisions, and the Center of Mass

Rotational Motion

Elastic Properties of Matter: Stress and Strain

Gravitation

Fluids

Oscillations

Waves

Thermodynamics I

Thermodynamics II

Electrostatics I: Electric Charge, Forces, and Fields

Electrostatics II: Electric Potential Energy and Electric Potential

Electric Charges in Motion

Magnetism

Electromagnetic Induction

Alternating-Current Circuits

Electromagnetic Waves

Wave Properties of Light

Geometrical Optics

Relativity

Quantum Physics and Atomic Structure

Nuclear Physics

Particle Physics

Filters

A car going around a curve of radius R at a speed V experiences a centripetal acceleration a_c. What should be the radius of the path that leads to twice the centripetal acceleration while it travels at the same speed V?

The curve shows the position of an object with time. The object moves with a constant speed, v. Which of the vector diagrams below best represent the change in velocity vector from P₁ to P₂?

The curve shows the position of an object with time. The object moves with a constant speed, v. Which of the vector diagrams below best represent the velocity vector at P₁ and P₂?