Question

Assertion (A) : The velocity of a projectile at a point on its trajectory is equal to the slope at that point.
Reason (R): The velocity vector at a point is always along the tangent to the trajectory at that point.

• A. Both (A) and (R) are true and (R) is the collect explanation of (A)
• B. Both (A) and (R) are true but (R) is not the con ect explanation of (A)
• C. (A) is tiue but (R) is false
• D. (A) is false but (R) is true

Answer 1

Answer: (D)

Trajectory of a projectice is of form
$y=f(x)=x \tan \theta-\frac{g x^{2}}{2 u^{2} \cos ^{2} \theta}$
$\therefore \frac{d y}{d x}=$ slope $=\frac{d y / d t}{d x / d t}=\frac{v_{y}}{v_{x}}$
So, Assertion (A) is incorrect. Also,
velocity of a projectile is always along tangent to the trajectory (shown)

Hence, reason $(R)$ is correct