Practice important
Projectile Components
MCQ questions and answers.
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MCQ Questions
1. A projectile is launched with speed u at an angle θ above the horizontal. What is its horizontal component of initial velocity?
A.
u sin θ
B.
u cos θ
C.
u tan θ
D.
u
Correct Answer:
u cos θ
Explanation:
The initial velocity is resolved into perpendicular components. The horizontal component is the adjacent component of the velocity triangle, so it is u cos θ.
2. A projectile is launched with speed u at an angle θ above the horizontal. What is its vertical component of initial velocity?
A.
u cos θ
B.
u tan θ
C.
u sin θ
D.
u
Correct Answer:
u sin θ
Explanation:
The vertical component is the opposite component in the velocity triangle, so the initial vertical velocity is u sin θ.
3. A ball is projected horizontally from a height. What is its initial vertical component of velocity?
A.
Equal to its horizontal component
B.
Zero
C.
Equal to its speed
D.
Greater than its horizontal component
Correct Answer:
Zero
Explanation:
For horizontal projection, the initial velocity is entirely horizontal. Therefore, its initial vertical component is zero.
4. A projectile is thrown vertically upward. What is its horizontal component of velocity?
A.
Zero
B.
Equal to its vertical component
C.
Equal to its initial speed
D.
Maximum at the highest point
Correct Answer:
Zero
Explanation:
A vertically upward throw has velocity only in the vertical direction, so its horizontal component is zero.
5. For a projectile moving through the air without air resistance, which component of velocity remains constant?
A.
Vertical component
B.
Horizontal component
C.
Both components increase
D.
Both components decrease
Correct Answer:
Horizontal component
Explanation:
Gravity acts vertically downward and does not affect horizontal motion. Hence, the horizontal component of velocity remains constant.
6. For a projectile moving upward, what happens to its vertical component of velocity?
A.
It remains constant
B.
It increases due to gravity
C.
It decreases due to gravity
D.
It becomes equal to the horizontal component immediately
Correct Answer:
It decreases due to gravity
Explanation:
Gravity acts downward, opposite to the upward vertical motion, so the vertical component of velocity decreases as the projectile rises.
7. At the highest point of a projectile's path, what is the value of its vertical component of velocity?
A.
Equal to its initial vertical component
B.
Zero
C.
Equal to its horizontal component
D.
Maximum
Correct Answer:
Zero
Explanation:
At the highest point, the projectile momentarily stops moving upward before moving downward. Therefore, its vertical velocity component is zero.
8. A projectile is launched at an angle of 0° to the horizontal. Which statement about its initial velocity components is correct?
A.
Horizontal component is zero and vertical component is maximum
B.
Both components are zero
C.
Horizontal component equals the launch speed and vertical component is zero
D.
Both components equal the launch speed
Correct Answer:
Horizontal component equals the launch speed and vertical component is zero
Explanation:
For θ = 0°, the horizontal component is u cos 0° = u and the vertical component is u sin 0° = 0.
9. A projectile is launched at an angle of 90° to the horizontal. Which statement about its initial velocity components is correct?
A.
Horizontal component equals the launch speed and vertical component is zero
B.
Horizontal component is zero and vertical component equals the launch speed
C.
Both components equal half the launch speed
D.
Both components are zero
Correct Answer:
Horizontal component is zero and vertical component equals the launch speed
Explanation:
For θ = 90°, the horizontal component is u cos 90° = 0 and the vertical component is u sin 90° = u.
10. A projectile is launched with speed 20 m/s at an angle of 30° above the horizontal. Taking sin 30° = 0.5, what is its initial vertical component of velocity?
A.
5 m/s
B.
10 m/s
C.
15 m/s
D.
20 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.