Practice important
Initial Velocity
MCQ questions and answers.
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MCQ Questions
1. A projectile is launched with an initial speed of 20 m/s at an angle of 30° above the horizontal. What is its initial horizontal velocity component?
A.
10 m/s
B.
17.3 m/s
C.
20 m/s
D.
34.6 m/s
Correct Answer:
17.3 m/s
Explanation:
The horizontal component of initial velocity is u cos θ = 20 cos 30° = 17.3 m/s.
2. A ball is projected with an initial speed of 10 m/s at an angle of 30° above the horizontal. What is its initial vertical velocity component?
A.
5 m/s
B.
8.66 m/s
C.
10 m/s
D.
20 m/s
Correct Answer:
5 m/s
Explanation:
The vertical component of initial velocity is u sin θ = 10 sin 30° = 5 m/s.
3. A projectile is thrown horizontally with a speed of 15 m/s. What are its initial horizontal and vertical velocity components?
A.
0 m/s and 15 m/s
B.
15 m/s and 15 m/s
C.
15 m/s and 0 m/s
D.
7.5 m/s and 7.5 m/s
Correct Answer:
15 m/s and 0 m/s
Explanation:
For a horizontal projection, the entire initial velocity is horizontal, so the horizontal component is 15 m/s and the vertical component is zero.
4. A projectile is launched vertically upward with an initial speed of 12 m/s. What is its initial horizontal velocity component?
A.
0 m/s
B.
6 m/s
C.
12 m/s
D.
24 m/s
Correct Answer:
0 m/s
Explanation:
A vertically upward projection has no horizontal component of initial velocity.
5. A projectile has initial velocity components of 6 m/s horizontally and 8 m/s vertically upward. What is its initial speed?
A.
2 m/s
B.
10 m/s
C.
14 m/s
D.
48 m/s
Correct Answer:
10 m/s
Explanation:
The initial speed is the magnitude of the velocity vector: u = √(6² + 8²) = 10 m/s.
6. A projectile is launched with an initial speed of 25 m/s at an angle of 53° above the horizontal. Using sin 53° = 0.8, what is its initial vertical velocity component?
A.
5 m/s
B.
15 m/s
C.
20 m/s
D.
25 m/s
Correct Answer:
20 m/s
Explanation:
The initial vertical component is u sin θ = 25 × 0.8 = 20 m/s.
7. A projectile is launched with an initial speed of 20 m/s at an angle of 60° above the horizontal. What is its initial vertical velocity component?
A.
10 m/s
B.
17.3 m/s
C.
20 m/s
D.
34.6 m/s
Correct Answer:
17.3 m/s
Explanation:
The vertical component is u sin θ = 20 sin 60° = 20 × 0.866 ≈ 17.3 m/s.
8. A projectile is launched with an initial speed of 20 m/s at an angle of 60° above the horizontal. What is its initial horizontal velocity component?
A.
10 m/s
B.
17.3 m/s
C.
20 m/s
D.
40 m/s
Correct Answer:
10 m/s
Explanation:
The horizontal component is u cos θ = 20 cos 60° = 10 m/s.
9. A projectile is launched with an initial velocity of 10 m/s at an angle of 45° above the horizontal. What is its initial horizontal component?
A.
5 m/s
B.
7.1 m/s
C.
10 m/s
D.
14.1 m/s
Correct Answer:
7.1 m/s
Explanation:
The horizontal component is u cos 45° = 10 × 0.707 ≈ 7.1 m/s.
10. A projectile has an initial horizontal velocity of 12 m/s and an initial vertical velocity of 5 m/s upward. What is the direction of its initial velocity approximately above the horizontal?