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.
5 m/s
Correct Answer:
17.3 m/s
Explanation:
The initial horizontal component is u cos θ = 20 cos 30° = 20 × 0.866 ≈ 17.3 m/s.
2. A projectile is launched with an initial speed of 20 m/s at an angle of 30° above the horizontal. What is its initial vertical velocity component?
A.
10 m/s
B.
17.3 m/s
C.
20 m/s
D.
5 m/s
Correct Answer:
10 m/s
Explanation:
The initial vertical component is u sin θ = 20 sin 30° = 20 × 0.5 = 10 m/s.
3. A ball is projected horizontally with a speed of 12 m/s. What is its initial vertical velocity component?
A.
12 m/s
B.
6 m/s
C.
0 m/s
D.
9.8 m/s
Correct Answer:
0 m/s
Explanation:
For a horizontal projection, the initial angle is 0°, so the initial vertical component is u sin 0° = 0 m/s.
4. A projectile is thrown vertically upward with an initial speed of 15 m/s. What is its initial horizontal velocity component?
A.
15 m/s
B.
7.5 m/s
C.
9.8 m/s
D.
0 m/s
Correct Answer:
0 m/s
Explanation:
For a vertical projection, the initial angle is 90°, so the initial horizontal component is u cos 90° = 0 m/s.
5. The initial velocity of a projectile has horizontal and vertical components of 6 m/s and 8 m/s, respectively. 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 initial velocity: u = √(6² + 8²) = √100 = 10 m/s.
6. A projectile has initial velocity components of 10 m/s horizontally and 10 m/s vertically upward. At what angle is it projected above the horizontal?
A.
30°
B.
45°
C.
60°
D.
90°
Correct Answer:
45°
Explanation:
The projection angle satisfies tan θ = initial vertical component / initial horizontal component = 10/10 = 1, so θ = 45°.
7. A projectile is launched with an initial speed of 10 m/s at an angle of 60° above the horizontal. What is its initial vertical velocity component?
A.
5 m/s
B.
8.66 m/s
C.
10 m/s
D.
4.33 m/s
Correct Answer:
8.66 m/s
Explanation:
The initial vertical component is u sin θ = 10 sin 60° = 10 × 0.866 ≈ 8.66 m/s.
8. A projectile is launched with an initial speed of 10 m/s at an angle of 60° above the horizontal. What is its initial horizontal velocity component?
A.
5 m/s
B.
8.66 m/s
C.
10 m/s
D.
6.67 m/s
Correct Answer:
5 m/s
Explanation:
The initial horizontal component is u cos θ = 10 cos 60° = 10 × 0.5 = 5 m/s.
9. A projectile has an initial horizontal velocity of 8 m/s and an initial vertical velocity of 6 m/s. What is the direction of its initial velocity?
A.
30° above the horizontal
B.
37° above the horizontal
C.
45° above the horizontal
D.
60° above the horizontal
Correct Answer:
37° above the horizontal
Explanation:
The angle is given by tan θ = 6/8 = 0.75, which gives θ ≈ 37° above the horizontal.
10. A projectile is launched at an angle of 0° with an initial speed of 25 m/s. What is its initial velocity in the vertical direction?
A.
25 m/s upward
B.
12.5 m/s upward
C.
25 m/s downward
D.
0 m/s
Correct Answer:
0 m/s
Explanation:
Since the launch angle is 0°, the projectile has no initial vertical component: u sin 0° = 0 m/s.