Grade 11 Projectile and Equilibrium Physics Practice Quiz (19 questions)

Question 1

1. Which feature distinguishes a velocity vector from speed?

Velocity includes both magnitude and direction

Velocity measures magnitude while speed gives direction

Velocity and speed both contain magnitude and direction

Velocity describes direction without a magnitude

Explanation

A velocity vector specifies how fast an object moves and in which direction. Speed is a scalar that gives magnitude without directional information.

Answer

Velocity includes both magnitude and direction

Question 2

2. A velocity has magnitude $20\,\text{m/s}$ at an angle of $30^\circ$ above the horizontal; what are its components?

v_x=20\,\text{m/s}

and

v_y=30\,\text{m/s}

v_x=17.3\,\text{m/s}

and

v_y=10\,\text{m/s}

v_x=10\,\text{m/s}

and

v_y=17.3\,\text{m/s}

v_x=14.1\,\text{m/s}

and

v_y=14.1\,\text{m/s}

Explanation

Because the angle is measured from the horizontal, the horizontal component is $v_x=v\cos\theta$ and the vertical component is $v_y=v\sin\theta$ , giving approximately $17.3\,\text{m/s}$ and $10\,\text{m/s}$ . Using sine for the horizontal component would interchange these values.

Answer

$$v_x=17.3\,\text{m/s}$$ and $$v_y=10\,\text{m/s}$$

Question 3

3. How is the velocity of object B relative to object A calculated?

\vec v_{B/A}=\vec v_B-\vec v_A

\vec v_{B/A}=\vec v_B+\vec v_A

\vec v_{B/A}=\left|\vec v_B\right|+\left|\vec v_A\right|

\vec v_{B/A}=\vec v_A-\vec v_B

Explanation

Relative velocity is found by subtracting the reference object's velocity from the observed object's velocity, so $\vec v_{B/A}=\vec v_B-\vec v_A$ . Adding the velocities does not represent the motion of B as seen from A.

Answer

$$\vec v_{B/A}=\vec v_B-\vec v_A$$

Question 4

4. A boat points perpendicular to a riverbank while its speed relative to the water stays fixed; what happens if the current becomes faster?

Both crossing time and downstream drift decrease

Both crossing time and downstream drift remain fixed

The crossing time stays fixed while downstream drift increases

The crossing time increases while drift stays fixed

Explanation

The perpendicular boat component determines the time needed to cross, while the current determines downstream drift. With the perpendicular speed fixed, a faster current increases drift but does not change crossing time.

Answer

The crossing time stays fixed while downstream drift increases

Question 5

5. A boat has perpendicular velocity components of $3\,\text{m/s}$ and $4\,\text{m/s}$ ; what is its resultant speed?

5\,\text{m/s}

7\,\text{m/s}

1\,\text{m/s}

12\,\text{m/s}

Explanation

Perpendicular velocities combine through the square-root sum of squares: $v=\sqrt{3^2+4^2}=5\,\text{m/s}$ . Direct addition would apply to collinear velocities rather than perpendicular components.

Answer

$$5\,\text{m/s}$$

Question 6

6. A boat crosses a river with no downstream drift when its upstream velocity component satisfies which condition?

v\cos\theta=v_c

v\tan\theta=v_c

v\sin\theta=\frac{1}{v_c}

v\sin\theta=v_c

Explanation

No downstream drift occurs when the upstream component balances the current, expressed as $v\sin\theta=v_c$ . The cosine component corresponds to the other directional component under the stated angle convention.

Answer

$$v\sin\theta=v_c$$

Question 7

7. What initial velocity characterizes a horizontal projectile?

A nonzero vertical velocity directed upward

A vertical velocity and zero horizontal velocity

Equal horizontal and vertical velocity components

A horizontal velocity and zero vertical velocity

Explanation

A horizontal projectile is launched with horizontal velocity while its initial vertical velocity is zero. An angled launch has a nonzero initial vertical component, so it represents a different type of projectile motion.

Answer

A horizontal velocity and zero vertical velocity

Question 8

8. A horizontal projectile is launched from a height of $20\,\text{m}$ with $g=10\,\text{m/s^2}$ ; how long does it remain in flight?

2\,\text{s}

10\,\text{s}

1\,\text{s}

4\,\text{s}

Explanation

The flight time is determined by the vertical drop: $t=\sqrt{\frac{2h}{g}}=\sqrt{\frac{40}{10}}=2\,\text{s}$ . Horizontal launch speed affects range but not the time required to fall from a given height.

Answer

$$2\,\text{s}$$

Question 9

9. A projectile is launched at speed $v_0$ and angle $\theta$ on level ground. Which expression gives its total flight time?

\frac{2v_0\sin\theta}{g}

\frac{v_0\sin\theta}{2g}

\frac{2v_0\cos\theta}{g}

\frac{v_0\cos\theta}{2g}

Explanation

The total flight time depends on the initial vertical component, $v_0\sin\theta$ , and is $\frac{2v_0\sin\theta}{g}$ . The horizontal component, $v_0\cos\theta$ , determines horizontal motion and range rather than flight time.

Answer

$$\frac{2v_0\sin\theta}{g}$$

Question 10

10. A projectile is launched at speed $v_0$ and angle $\theta$ above level ground. How long does it take to reach maximum height?

\frac{v_0\sin\theta}{g}

\frac{v_0\cos\theta}{g}

\frac{v_0\sin\theta}{2g}

\frac{2v_0\sin\theta}{g}

Explanation

At maximum height, the initial vertical velocity has been reduced to zero by downward acceleration, giving $t_{max}=\frac{v_0\sin\theta}{g}$ . The acceleration remains downward with magnitude $g$ even when the vertical velocity is zero.

Answer

$$\frac{v_0\sin\theta}{g}$$

Question 11

11. For a projectile launched on level ground with speed $v_0$ at angle $\theta$ , which expression gives its maximum height?

\frac{v_0^2\cos^2\theta}{2g}

\frac{v_0^2\sin^2\theta}{2g}

\frac{2v_0^2\sin^2\theta}{g}

\frac{v_0\sin\theta}{2g}

Explanation

The maximum height is determined by the initial vertical component and equals $H=\frac{v_0^2\sin^2\theta}{2g}$ . Using the horizontal component would describe horizontal motion rather than vertical rise.

Answer

$$\frac{v_0^2\sin^2\theta}{2g}$$

Question 12

12. For a fixed launch speed on level ground, which launch angle produces the greatest horizontal range?

45°

60°

90°

30°

Explanation

For a fixed initial speed and equal launch and landing heights, the maximum range occurs at a launch angle of 45°. Angles such as 30° and 60° can produce equal ranges to each other, but not the greatest range.

Answer

The turning effect of the force

Answer

$$6.0\,\mathrm{N\,m}$$

Answer

$$FL\sin\theta$$

Answer

When the vector sum of its forces is zero

Answer

When the algebraic sum of its moments is zero

Answer

$$\sum \vec F=0$$

Question 13

13. What does the moment of a force describe about a pivot?

The pressure exerted by the force

The turning effect of the force

The mass carried by the force

The speed gained from the force

Explanation

The moment of a force describes its tendency to produce rotation about a pivot. Force by itself measures an interaction, not the rotational effect associated with a particular pivot.

Question 14

14. A force of $12\,\mathrm{N}$ acts with a perpendicular distance of $0.50\,\mathrm{m}$ from a pivot. What moment does it produce?

12.5\,\mathrm{N\,m}

24\,\mathrm{N\,m}

0.042\,\mathrm{N\,m}

6.0\,\mathrm{N\,m}

Explanation

Using $\tau=Fd$ gives $\tau=(12\,\mathrm{N})(0.50\,\mathrm{m})=6.0\,\mathrm{N\,m}$ . The relevant distance is the perpendicular distance to the line of action, not a different length measured along the lever.

Question 15

15. A force $F$ acts at angle $\theta$ to a lever of length $L$ . Which expression gives its moment about the pivot?

FL\sin\theta

\frac{FL}{\sin\theta}

FL\cos\theta

\frac{F\sin\theta}{L}

Explanation

The moment is $\tau=FL\sin\theta$ because the perpendicular component of the force produces the turning effect. The cosine expression would correspond to selecting the wrong component for the stated angle.

Question 16

16. What is the moment about a pivot of a force whose line of action passes through that pivot?

Equal to the lever length

Maximum for that force

Equal to the force magnitude

Zero

Explanation

A force whose line of action passes through the pivot has zero perpendicular distance, so $\tau=Fd=0$ . A nonzero moment requires a perpendicular separation between the pivot and the line of action.

Question 17

17. When is a body in translational equilibrium?

When its speed is increasing uniformly

When one force acts through its center

When the vector sum of its forces is zero

When the algebraic sum of its moments is zero

Explanation

Translational equilibrium requires the vector sum of all forces to be zero, so there is no linear acceleration. A zero moment sum describes rotational equilibrium rather than translational equilibrium.

Question 18

18. When is a body in rotational equilibrium about a pivot?

When its angular speed is increasing steadily

When the vector sum of its forces is zero

When the algebraic sum of its moments is zero

When its weight acts through the pivot

Explanation

Rotational equilibrium occurs when clockwise and counterclockwise moments balance so that the algebraic moment sum is zero. A zero net force instead establishes translational equilibrium and does not by itself balance rotation.

Question 19

19. Which equation represents translational equilibrium for a body?

\sum \vec F=0

\sum \tau=I\alpha

\sum \tau=0

\sum \vec F=m\vec a

Explanation

For translational equilibrium, the vector sum of all forces satisfies $\sum \vec F=0$ . The moment equations describe rotational behavior, while a nonzero force sum corresponds to linear acceleration.

Grade 11 Projectile and Equilibrium Physics Practice Quiz (19 questions)

All questions and answers

1. Which feature distinguishes a velocity vector from speed?

2. A velocity has magnitude $20\,\text{m/s}$ at an angle of $30^\circ$ above the horizontal; what are its components?

3. How is the velocity of object B relative to object A calculated?

4. A boat points perpendicular to a riverbank while its speed relative to the water stays fixed; what happens if the current becomes faster?

5. A boat has perpendicular velocity components of $3\,\text{m/s}$ and $4\,\text{m/s}$ ; what is its resultant speed?

6. A boat crosses a river with no downstream drift when its upstream velocity component satisfies which condition?

7. What initial velocity characterizes a horizontal projectile?

8. A horizontal projectile is launched from a height of $20\,\text{m}$ with $g=10\,\text{m/s^2}$ ; how long does it remain in flight?

9. A projectile is launched at speed $v_0$ and angle $\theta$ on level ground. Which expression gives its total flight time?

10. A projectile is launched at speed $v_0$ and angle $\theta$ above level ground. How long does it take to reach maximum height?

11. For a projectile launched on level ground with speed $v_0$ at angle $\theta$ , which expression gives its maximum height?

12. For a fixed launch speed on level ground, which launch angle produces the greatest horizontal range?

13. What does the moment of a force describe about a pivot?

14. A force of $12\,\mathrm{N}$ acts with a perpendicular distance of $0.50\,\mathrm{m}$ from a pivot. What moment does it produce?

15. A force $F$ acts at angle $\theta$ to a lever of length $L$ . Which expression gives its moment about the pivot?

16. What is the moment about a pivot of a force whose line of action passes through that pivot?

17. When is a body in translational equilibrium?

18. When is a body in rotational equilibrium about a pivot?

19. Which equation represents translational equilibrium for a body?

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Grade 11 Projectile and Equilibrium Physics Practice Quiz (19 questions)

All questions and answers

1. Which feature distinguishes a velocity vector from speed?

2. A velocity has magnitude 20 m/s20\,\text{m/s}20m/s at an angle of 30∘30^\circ30∘ above the horizontal; what are its components?

3. How is the velocity of object B relative to object A calculated?

4. A boat points perpendicular to a riverbank while its speed relative to the water stays fixed; what happens if the current becomes faster?

5. A boat has perpendicular velocity components of 3 m/s3\,\text{m/s}3m/s and 4 m/s4\,\text{m/s}4m/s; what is its resultant speed?

6. A boat crosses a river with no downstream drift when its upstream velocity component satisfies which condition?

7. What initial velocity characterizes a horizontal projectile?

8. A horizontal projectile is launched from a height of 20 m20\,\text{m}20m with g=10\,\text{m/s^2}; how long does it remain in flight?

9. A projectile is launched at speed v0v_0v0​ and angle θ\thetaθ on level ground. Which expression gives its total flight time?

10. A projectile is launched at speed v0v_0v0​ and angle θ\thetaθ above level ground. How long does it take to reach maximum height?

11. For a projectile launched on level ground with speed v0v_0v0​ at angle θ\thetaθ, which expression gives its maximum height?

12. For a fixed launch speed on level ground, which launch angle produces the greatest horizontal range?

13. What does the moment of a force describe about a pivot?

14. A force of 12 N12\,\mathrm{N}12N acts with a perpendicular distance of 0.50 m0.50\,\mathrm{m}0.50m from a pivot. What moment does it produce?

15. A force FFF acts at angle θ\thetaθ to a lever of length LLL. Which expression gives its moment about the pivot?

16. What is the moment about a pivot of a force whose line of action passes through that pivot?

17. When is a body in translational equilibrium?

18. When is a body in rotational equilibrium about a pivot?

19. Which equation represents translational equilibrium for a body?

Study with flashcards

Read the study guide

Related classes

Foundations of Political Science

Mathematical Communication Theory

Plant Organic Matter Production

Animal Kingdom Classification

Kinetic Theory and Gas Behavior

Healthy Lifestyle, Nutrition and Digestion

Make your own practice quizzes

2. A velocity has magnitude $20\,\text{m/s}$ at an angle of $30^\circ$ above the horizontal; what are its components?

5. A boat has perpendicular velocity components of $3\,\text{m/s}$ and $4\,\text{m/s}$ ; what is its resultant speed?

8. A horizontal projectile is launched from a height of $20\,\text{m}$ with $g=10\,\text{m/s^2}$ ; how long does it remain in flight?

9. A projectile is launched at speed $v_0$ and angle $\theta$ on level ground. Which expression gives its total flight time?

10. A projectile is launched at speed $v_0$ and angle $\theta$ above level ground. How long does it take to reach maximum height?

11. For a projectile launched on level ground with speed $v_0$ at angle $\theta$ , which expression gives its maximum height?

14. A force of $12\,\mathrm{N}$ acts with a perpendicular distance of $0.50\,\mathrm{m}$ from a pivot. What moment does it produce?

15. A force $F$ acts at angle $\theta$ to a lever of length $L$ . Which expression gives its moment about the pivot?