Assertion (A) The velocity of a projectile at a point on its trajectory is equal to the slope at that point.…
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
always along the tangent to the trajectory at
that point.
Both A and R are true and R is the correct
explanation of A
Both A and R are true but R is not the correct
explanation of A
A is true but R is false
A is false but R is true
Solution
Trajectory of a projectice is of form
$
\begin{aligned}
& y=f(x)=x \tan \theta-\frac{g x^2}{2 u^2 \cos ^2 \theta} \\
& \therefore \frac{d y}{d x}=\text { slope }=\frac{d y / d t}{d x / d t}=\frac{v_y}{v_x}
\end{aligned}
$
So, Assertion (A) is incorrect.
Also, velocity of a projectile is always along tangent to the trajectory (shown)
Hence, reason $(R)$ is correct
