Question

Assertion :In case of a projectile, the angle between velocity and acceleration changes from point to point. Reason: Because its horizontal component of velocity remains constant, while vertical component of velocity changes from point to point due to gravitational acceleration.

• A. Both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
• B. Both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.
• C. Assertion is true, but the Reason is false.
• D. Assertion is false, but the Reason is true.

Answer 1

Answer: (A)

At any point in a projectile velocity and acceleration components are given as :

$V_x=V\cos \theta ,a_x=0$
$V_y=V\sin \theta -gt,a_y=-g$

Angle from the vertical is given as $\tan \theta =\frac{V_y}{V_x}$

$\theta$ changes as $v_y$ changes

At every point the velocity is changing and pointing along the direction of the motion of the projectile whereas the acceleration always acts in the downward direction.